Line Chart¶

This section showcases the line chart. It contains examples of how to create line charts using the datachart.charts.LineChart function.

The examples sequentially build on each other, going from simple to more complex.

As mentioned above, the line charts are created using the LineChart function found in the datachart.charts module. Let's import it:

In [1]:

from datachart.charts import LineChart

from datachart.charts import LineChart

Double figure generation avoidence

To avoid double figure generation, the LineChart function is preceded by the _ = operator. The double figures are generated because LineChart returns the plt.Figure object, which is then used to save the figure locally.

Line Chart Input Attributes¶

The LineChart function accepts the attributes of the datachart.typings.LineChartAttrs type. In a nutshell, the input is a dict object containing the charts attribute, which is either a dict or a List[dict] where each dictionary contains some of the following attributes:

{
  "data": [{                                            # A list of line data points
    "x":    Union[int, float],                          # The x-axis value
    "y":    Union[int, float],                          # The y-axis value
    "yerr": Optional[Union[int, float]]                 # The y-axis error value (to plot the confidence interval)
  }],
  "style": {                                            # The style of the line (optional)
    "plot_line_color":     Optional[str],               # The color of the line (hex color code)
    "plot_line_style":     Optional[LINE_STYLE],        # The line style (solid, dashed, etc.)
    "plot_line_marker":    Optional[LINE_MARKER],       # The marker style of the line (circle, square, etc.)
    "plot_line_width":     Optional[float],             # The width of the line
    "plot_line_alpha":     Optional[float],             # The alpha of the line (how visible the line is)
    "plot_line_drawstyle": Optional[LINE_DRAW_STYLE],   # The drawstyle of the line (step, steps-mid, etc.)
    "plot_line_zorder":    Optional[int],               # The zorder of the line
  },
  "subtitle": Optional[str],                            # The title of the chart
  "xlabel":   Optional[str],                            # The x-axis label
  "ylabel":   Optional[str],                            # The y-axis label

  "xticks": Optional[List[Union[int, float]]],          # the x-axis ticks
  "xticklabels": Optional[List[Union[str, float, str]], # the x-axis tick labels (must be same length as xticks)
  "xtickrotate": Optional[int],                         # the x-axis tick labels rotation
  "yticks": Optional[List[Union[int, float]]],          # the y-axis ticks
  "yticklabels": Optional[List[Union[str, float, str]], # the y-axis tick labels (must be same length as yticks)
  "ytickrotate": Optional[int],                         # the y-axis tick labels rotation

  "vlines": Optional[Union[dict, None]],                # the vertical lines (see below for more details)
  "hlines": Optional[Union[dict, None]],                # the horizontal lines (see below for more details)
}

For more details, see the datachart.typings.LineChartAttrs type.

Single Line Chart¶

In this part, we show how to create a single line chart using the LineChart function.

Let us first import the necessary libraries:

In [2]:

import numpy as np

import numpy as np

Basic example. Let us first create a basic line chart showing the cosine function.

The following example shows how only the charts["data"] attribute is required to draw the line chart.

In [3]:

_ = LineChart(
    {
        # add the data to the chart
        "charts": {
            "data": [{"x": x / 10, "y": np.cos(x / 2)} for x in range(21)],
        }
    }
)

_ = LineChart( { # add the data to the chart "charts": { "data": [{"x": x / 10, "y": np.cos(x / 2)} for x in range(21)], } } )

Chart title and axis labels¶

To add the chart title and axis labels, simply add the title, xlabel and ylabel attributes.

In [4]:

_ = LineChart(
    {
        "charts": {
            "data": [{"x": x / 10, "y": np.cos(x / 2)} for x in range(21)],
        },
        # add the title
        "title": "Title",
        # add the x and y axis labels
        "xlabel": "the global x-axis label",
        "ylabel": "the global y-axis label",
    }
)

_ = LineChart( { "charts": { "data": [{"x": x / 10, "y": np.cos(x / 2)} for x in range(21)], }, # add the title "title": "Title", # add the x and y axis labels "xlabel": "the global x-axis label", "ylabel": "the global y-axis label", } )

Figure size and grid¶

To change the figure size, simply add the figsize attribute. The figsize attribute can be a tuple (width, height), values are in inches. The datachart package provides a datachart.constants.FIG_SIZE constant, which contains some of the predefined figure sizes.

To add the grid, simply add the show_grid attribute. The possible options are:

Option	Description
"both"	shows both the x-axis and the y-axis gridlines.
"x"	shows only the x-axis grid lines.
"y"	shows only the y-axis grid lines.

Again, datachart provides a datachart.constants.SHOW_GRID constant, which contains the supported options.

In [5]:

from datachart.constants import FIG_SIZE, SHOW_GRID

from datachart.constants import FIG_SIZE, SHOW_GRID

In [6]:

_ = LineChart(
    {
        "charts": {
            "data": [{"x": x / 10, "y": np.cos(x / 2)} for x in range(21)],
        },
        "title": "Title",
        "xlabel": "the global x-axis label",
        "ylabel": "the global y-axis label",
        # add to determine the figure size
        "figsize": FIG_SIZE.A4_NARROW,
        # add to show the grid lines
        "show_grid": SHOW_GRID.BOTH,
    }
)

_ = LineChart( { "charts": { "data": [{"x": x / 10, "y": np.cos(x / 2)} for x in range(21)], }, "title": "Title", "xlabel": "the global x-axis label", "ylabel": "the global y-axis label", # add to determine the figure size "figsize": FIG_SIZE.A4_NARROW, # add to show the grid lines "show_grid": SHOW_GRID.BOTH, } )

Line style¶

To change a single line style simply add the style attribute with the corresponding attributes. The supported attributes are shown in the datachart.typings.LineStyleAttrs type, which contains the following attributes:

Attribute	Description
"plot_line_color"	The color of the line (hex color code).
"plot_line_alpha"	The alpha of the line (how visible the line is).
"plot_line_width"	The width of the line.
"plot_line_style"	The line style (solid, dashed, etc.).
"plot_line_marker"	The marker style of the line (circle, square, etc.).
"plot_line_drawstyle"	The drawstyle of the line (step, steps-mid, etc.).
"plot_line_zorder"	The zorder of the line.

Again, to help with the style settings, the datachart.constants module contains the following constants:

Constant	Description
datachart.constants.LINE_STYLE	The line style (solid, dashed, etc.)
datachart.constants.LINE_MARKER	The marker style of the line (circle, square, etc.)
datachart.constants.LINE_DRAW_STYLE	The drawstyle of the line (step, steps-mid, etc.)

In [7]:

from datachart.constants import LINE_STYLE, LINE_MARKER, LINE_DRAW_STYLE

from datachart.constants import LINE_STYLE, LINE_MARKER, LINE_DRAW_STYLE

In [8]:

_ = LineChart(
    {
        "charts": {
            "data": [{"x": x / 10, "y": np.cos(x / 2)} for x in range(21)],
            # define the style of the line
            "style": {
                "plot_line_style": LINE_STYLE.DOTTED,
                "plot_line_marker": LINE_MARKER.POINT,
                "plot_line_drawstyle": LINE_DRAW_STYLE.STEPS_MID,
            },
        },
        "title": "Title",
        "xlabel": "the global x-axis label",
        "ylabel": "the global y-axis label",
        "figsize": FIG_SIZE.A4_NARROW,
        "show_grid": SHOW_GRID.BOTH,
    }
)

_ = LineChart( { "charts": { "data": [{"x": x / 10, "y": np.cos(x / 2)} for x in range(21)], # define the style of the line "style": { "plot_line_style": LINE_STYLE.DOTTED, "plot_line_marker": LINE_MARKER.POINT, "plot_line_drawstyle": LINE_DRAW_STYLE.STEPS_MID, }, }, "title": "Title", "xlabel": "the global x-axis label", "ylabel": "the global y-axis label", "figsize": FIG_SIZE.A4_NARROW, "show_grid": SHOW_GRID.BOTH, } )

Area under the line¶

To add the area under the line, simply add the show_area attribute into the input dictionary.

In [9]:

_ = LineChart(
    {
        "charts": {
            "data": [{"x": x / 10, "y": np.cos(x / 2)} for x in range(21)],
            "style": {
                "plot_line_style": LINE_STYLE.DOTTED,
                "plot_line_marker": LINE_MARKER.POINT,
                "plot_line_drawstyle": LINE_DRAW_STYLE.STEPS_MID,
            },
        },
        "title": "Title",
        "xlabel": "the global x-axis label",
        "ylabel": "the global y-axis label",
        "figsize": FIG_SIZE.A4_NARROW,
        "show_grid": SHOW_GRID.BOTH,
        # shows the area between the line and y=0
        "show_area": True,
    }
)

_ = LineChart( { "charts": { "data": [{"x": x / 10, "y": np.cos(x / 2)} for x in range(21)], "style": { "plot_line_style": LINE_STYLE.DOTTED, "plot_line_marker": LINE_MARKER.POINT, "plot_line_drawstyle": LINE_DRAW_STYLE.STEPS_MID, }, }, "title": "Title", "xlabel": "the global x-axis label", "ylabel": "the global y-axis label", "figsize": FIG_SIZE.A4_NARROW, "show_grid": SHOW_GRID.BOTH, # shows the area between the line and y=0 "show_area": True, } )

Adding vertical and horizontal lines¶

Adding vertical lines. Within the charts attribute, define the attribute vlines with the datachart.typings.VLinePlotAttrs typing, which is either a dict or a List[dict] where each dictionary contains some of the following attributes:

{
  "x":    Union[int, float],                  # The x-axis value
  "ymin": Optional[Union[int, float]],        # The minimum y-axis value
  "ymax": Optional[Union[int, float]],        # The maximum y-axis value
  "style": {                                  # The style of the line (optional)
    "plot_vline_color": Optional[str],        # The color of the line (hex color code)
    "plot_vline_style": Optional[LINE_STYLE], # The line style (solid, dashed, etc.)
    "plot_vline_width": Optional[float],      # The width of the line
    "plot_vline_alpha": Optional[float],      # The alpha of the line (how visible the line is)
  },
  "label": Optional[str],                     # The label of the line
}

Adding horizontal lines. Within the charts attribute, define the attribute hlines, with the datachart.typings.HLinePlotAttrs typing, which is either a dict or a List[dict] where each dictionary contains some of the following attributes:

{
  "y":    Union[int, float],                  # The y-axis value
  "xmin": Optional[Union[int, float]],        # The minimum x-axis value
  "xmax": Optional[Union[int, float]],        # The maximum x-axis value
  "style": {                                  # The style of the line (optional)
    "plot_hline_color": Optional[str],        # The color of the line (hex color code)
    "plot_hline_style": Optional[LINE_STYLE], # The line style (solid, dashed, etc.)
    "plot_hline_width": Optional[float],      # The width of the line
    "plot_hline_alpha": Optional[float],      # The alpha of the line (how visible the line is)
  },
  "label": Optional[str],                     # The label of the line
}

To add vertical and horizontal lines, simply add the vlines and hlines attributes into the input dictionary.

In [10]:

_ = LineChart(
    {
        "charts": {
            "data": [{"x": x / 10, "y": np.cos(x / 2)} for x in range(21)],
            "style": {
                "plot_line_style": LINE_STYLE.DOTTED,
                "plot_line_marker": LINE_MARKER.POINT,
                "plot_line_drawstyle": LINE_DRAW_STYLE.STEPS_MID,
            },
            # add a list of vertical lines
            "vlines": [
                {
                    "x": 0.5 * i,
                    "style": {
                        "plot_vline_color": "green",
                        "plot_vline_style": LINE_STYLE.SOLID,
                        "plot_vline_width": 1,
                    },
                }
                for i in range(1, 4)
            ],
            # add a list of horizontal lines
            "hlines": {
                "y": 0,
                "style": {
                    "plot_hline_color": "red",
                    "plot_hline_style": LINE_STYLE.DASHED,
                    "plot_hline_width": 2,
                    "plot_hline_alpha": 0.5,
                },
            },
        },
        "title": "Title",
        "xlabel": "the global x-axis label",
        "ylabel": "the global y-axis label",
        "figsize": FIG_SIZE.A4_NARROW,
        "show_grid": SHOW_GRID.BOTH,
    }
)

_ = LineChart( { "charts": { "data": [{"x": x / 10, "y": np.cos(x / 2)} for x in range(21)], "style": { "plot_line_style": LINE_STYLE.DOTTED, "plot_line_marker": LINE_MARKER.POINT, "plot_line_drawstyle": LINE_DRAW_STYLE.STEPS_MID, }, # add a list of vertical lines "vlines": [ { "x": 0.5 * i, "style": { "plot_vline_color": "green", "plot_vline_style": LINE_STYLE.SOLID, "plot_vline_width": 1, }, } for i in range(1, 4) ], # add a list of horizontal lines "hlines": { "y": 0, "style": { "plot_hline_color": "red", "plot_hline_style": LINE_STYLE.DASHED, "plot_hline_width": 2, "plot_hline_alpha": 0.5, }, }, }, "title": "Title", "xlabel": "the global x-axis label", "ylabel": "the global y-axis label", "figsize": FIG_SIZE.A4_NARROW, "show_grid": SHOW_GRID.BOTH, } )

Multiple Line Charts¶

To add multiple line charts, simply add the charts attribute with a list of charts, as shown below.

Attributes same as creating a single chart

We designed the datachart.charts.* functions to use the same attribute naming when possible. To create multiple charts, the charts attribute becomes a list of dictionaries with the same attributes as when creating a single chart.

In [11]:

_ = LineChart(
    {
        # use a list of charts to define multiple lines
        "charts": [
            {
                "data": [{"x": x / 10, "y": np.cos(x / 2)} for x in range(21)],
                "style": {
                    "plot_line_style": LINE_STYLE.DOTTED,
                    "plot_line_marker": LINE_MARKER.POINT,
                    "plot_line_drawstyle": LINE_DRAW_STYLE.STEPS_MID,
                },
            },
            {
                "data": [{"x": x / 10, "y": 2 * np.sin(x / 2)} for x in range(21)],
            },
        ],
        "title": "Title",
        "xlabel": "the global x-axis label",
        "ylabel": "the global y-axis label",
        "figsize": FIG_SIZE.A4_NARROW,
        "show_grid": SHOW_GRID.BOTH,
    }
)

_ = LineChart( { # use a list of charts to define multiple lines "charts": [ { "data": [{"x": x / 10, "y": np.cos(x / 2)} for x in range(21)], "style": { "plot_line_style": LINE_STYLE.DOTTED, "plot_line_marker": LINE_MARKER.POINT, "plot_line_drawstyle": LINE_DRAW_STYLE.STEPS_MID, }, }, { "data": [{"x": x / 10, "y": 2 * np.sin(x / 2)} for x in range(21)], }, ], "title": "Title", "xlabel": "the global x-axis label", "ylabel": "the global y-axis label", "figsize": FIG_SIZE.A4_NARROW, "show_grid": SHOW_GRID.BOTH, } )

Sub-chart subtitles¶

We can name each chart by adding the subtitle attribute to each chart. In addition, to help with discerning which chart is which, use the show_legend attribute to show the legend of the charts.

In [12]:

_ = LineChart(
    {
        "charts": [
            {
                "data": [{"x": x / 10, "y": np.cos(x / 2)} for x in range(21)],
                "style": {
                    "plot_line_style": LINE_STYLE.DOTTED,
                    "plot_line_marker": LINE_MARKER.POINT,
                    "plot_line_drawstyle": LINE_DRAW_STYLE.STEPS_MID,
                },
                # add a subtitle to the line
                "subtitle": "cosine",
            },
            {
                "data": [{"x": x / 10, "y": 2 * np.sin(x / 2)} for x in range(21)],
                # add a subtitle to the line
                "subtitle": "sine",
            },
        ],
        "title": "Title",
        "xlabel": "the global x-axis label",
        "ylabel": "the global y-axis label",
        "figsize": FIG_SIZE.A4_NARROW,
        "show_grid": SHOW_GRID.BOTH,
        # show the legend
        "show_legend": True,
    }
)

_ = LineChart( { "charts": [ { "data": [{"x": x / 10, "y": np.cos(x / 2)} for x in range(21)], "style": { "plot_line_style": LINE_STYLE.DOTTED, "plot_line_marker": LINE_MARKER.POINT, "plot_line_drawstyle": LINE_DRAW_STYLE.STEPS_MID, }, # add a subtitle to the line "subtitle": "cosine", }, { "data": [{"x": x / 10, "y": 2 * np.sin(x / 2)} for x in range(21)], # add a subtitle to the line "subtitle": "sine", }, ], "title": "Title", "xlabel": "the global x-axis label", "ylabel": "the global y-axis label", "figsize": FIG_SIZE.A4_NARROW, "show_grid": SHOW_GRID.BOTH, # show the legend "show_legend": True, } )

Subplots¶

To draw multiple charts in each subplot, simply add the subplots attribute. The chart's subtitle are then added at the top of each subplot, while the title, xlabel and ylabel are positioned to be global for all charts.

In [13]:

_ = LineChart(
    {
        "charts": [
            {
                "data": [{"x": x / 10, "y": np.cos(x / 2)} for x in range(21)],
                "style": {
                    "plot_line_style": LINE_STYLE.DOTTED,
                    "plot_line_marker": LINE_MARKER.POINT,
                    "plot_line_drawstyle": LINE_DRAW_STYLE.STEPS_MID,
                },
                "subtitle": "cosine",
            },
            {
                "data": [{"x": x / 10, "y": 2 * np.sin(x / 2)} for x in range(21)],
                "subtitle": "sine",
            },
        ],
        "title": "Title",
        "xlabel": "the global x-axis label",
        "ylabel": "the global y-axis label",
        "figsize": FIG_SIZE.A4_NARROW,
        "show_grid": SHOW_GRID.BOTH,
        # show each chart in its own subplot
        "subplots": True,
    }
)

_ = LineChart( { "charts": [ { "data": [{"x": x / 10, "y": np.cos(x / 2)} for x in range(21)], "style": { "plot_line_style": LINE_STYLE.DOTTED, "plot_line_marker": LINE_MARKER.POINT, "plot_line_drawstyle": LINE_DRAW_STYLE.STEPS_MID, }, "subtitle": "cosine", }, { "data": [{"x": x / 10, "y": 2 * np.sin(x / 2)} for x in range(21)], "subtitle": "sine", }, ], "title": "Title", "xlabel": "the global x-axis label", "ylabel": "the global y-axis label", "figsize": FIG_SIZE.A4_NARROW, "show_grid": SHOW_GRID.BOTH, # show each chart in its own subplot "subplots": True, } )

Sharing x-axis and/or y-axis across subplots¶

To share the x-axis and/or y-axis across subplots, simply add the sharex and/or sharey attributes, which are boolean values that specify whether to share the axis across all subplots.

In [14]:

_ = LineChart(
    {
        "charts": [
            {
                "data": [{"x": x / 10, "y": np.cos(x / 2)} for x in range(21)],
                "style": {
                    "plot_line_style": LINE_STYLE.DOTTED,
                    "plot_line_marker": LINE_MARKER.POINT,
                    "plot_line_drawstyle": LINE_DRAW_STYLE.STEPS_MID,
                },
                "subtitle": "cosine",
            },
            {
                "data": [{"x": x / 10, "y": 2 * np.sin(x / 2)} for x in range(21)],
                "subtitle": "sine",
            },
        ],
        "title": "Title",
        "xlabel": "the global x-axis label",
        "ylabel": "the global y-axis label",
        "figsize": FIG_SIZE.A4_NARROW,
        "show_grid": SHOW_GRID.BOTH,
        "subplots": True,
        # share the x-axis across all subplots
        "sharex": True,
        # share the y-axis across all subplots
        "sharey": True,
    }
)

_ = LineChart( { "charts": [ { "data": [{"x": x / 10, "y": np.cos(x / 2)} for x in range(21)], "style": { "plot_line_style": LINE_STYLE.DOTTED, "plot_line_marker": LINE_MARKER.POINT, "plot_line_drawstyle": LINE_DRAW_STYLE.STEPS_MID, }, "subtitle": "cosine", }, { "data": [{"x": x / 10, "y": 2 * np.sin(x / 2)} for x in range(21)], "subtitle": "sine", }, ], "title": "Title", "xlabel": "the global x-axis label", "ylabel": "the global y-axis label", "figsize": FIG_SIZE.A4_NARROW, "show_grid": SHOW_GRID.BOTH, "subplots": True, # share the x-axis across all subplots "sharex": True, # share the y-axis across all subplots "sharey": True, } )

Area under the lines¶

Specifying the show_area attribute will show the area between the line and y=0 across all subplots.

In [15]:

_ = LineChart(
    {
        "charts": [
            {
                "data": [{"x": x / 10, "y": np.cos(x / 2)} for x in range(21)],
                "style": {
                    "plot_line_style": LINE_STYLE.DOTTED,
                    "plot_line_marker": LINE_MARKER.POINT,
                    "plot_line_drawstyle": LINE_DRAW_STYLE.STEPS_MID,
                },
                "subtitle": "cosine",
            },
            {
                "data": [{"x": x / 10, "y": 2 * np.sin(x / 2)} for x in range(21)],
                "subtitle": "sine",
            },
        ],
        "title": "Title",
        "xlabel": "the global x-axis label",
        "ylabel": "the global y-axis label",
        "figsize": FIG_SIZE.A4_NARROW,
        "show_grid": SHOW_GRID.BOTH,
        "subplots": True,
        "sharex": True,
        "sharey": True,
        # show area between the line and y=0 for all subplots
        "show_area": True,
    }
)

_ = LineChart( { "charts": [ { "data": [{"x": x / 10, "y": np.cos(x / 2)} for x in range(21)], "style": { "plot_line_style": LINE_STYLE.DOTTED, "plot_line_marker": LINE_MARKER.POINT, "plot_line_drawstyle": LINE_DRAW_STYLE.STEPS_MID, }, "subtitle": "cosine", }, { "data": [{"x": x / 10, "y": 2 * np.sin(x / 2)} for x in range(21)], "subtitle": "sine", }, ], "title": "Title", "xlabel": "the global x-axis label", "ylabel": "the global y-axis label", "figsize": FIG_SIZE.A4_NARROW, "show_grid": SHOW_GRID.BOTH, "subplots": True, "sharex": True, "sharey": True, # show area between the line and y=0 for all subplots "show_area": True, } )

Confidence interval¶

If a line chart has a confidence interval, it can be added by adding the yerr attribute to the chart's data attribute. Afterwards, the show_yerr attribute can be set to True to show the confidence interval.

In [16]:

import random

import random

In [17]:

_ = LineChart(
    {
        "charts": [
            {
                "data": [
                    # add the error values for each point's y value
                    {"x": x / 10, "y": np.cos(x / 2), "yerr": 0.1 + random.random()}
                    for x in range(21)
                ],
                "style": {
                    "plot_line_style": LINE_STYLE.DOTTED,
                    "plot_line_marker": LINE_MARKER.POINT,
                    "plot_line_drawstyle": LINE_DRAW_STYLE.STEPS_MID,
                },
                "subtitle": "Subtitle",
                # add local subplot x-axis label
                "xlabel": "The local x-axis label",
                # add local subplot y-axis label
                "ylabel": "The local y-axis label",
            },
            {
                "data": [
                    # note: not all lines require to have the error values
                    {"x": x / 10, "y": 2 * np.sin(x / 2)}
                    for x in range(21)
                ],
                "subtitle": "Subtitle",
                # add local subplot x-axis label
                "xlabel": "The local x-axis label",
                # add local subplot y-axis label
                "ylabel": "The local y-axis label",
            },
        ],
        "title": "Title",
        "figsize": FIG_SIZE.A4_NARROW,
        "show_grid": SHOW_GRID.BOTH,
        "subplots": True,
        "sharex": True,
        "sharey": True,
        # show the confidence interval using the error values
        "show_yerr": True,
    }
)

_ = LineChart( { "charts": [ { "data": [ # add the error values for each point's y value {"x": x / 10, "y": np.cos(x / 2), "yerr": 0.1 + random.random()} for x in range(21) ], "style": { "plot_line_style": LINE_STYLE.DOTTED, "plot_line_marker": LINE_MARKER.POINT, "plot_line_drawstyle": LINE_DRAW_STYLE.STEPS_MID, }, "subtitle": "Subtitle", # add local subplot x-axis label "xlabel": "The local x-axis label", # add local subplot y-axis label "ylabel": "The local y-axis label", }, { "data": [ # note: not all lines require to have the error values {"x": x / 10, "y": 2 * np.sin(x / 2)} for x in range(21) ], "subtitle": "Subtitle", # add local subplot x-axis label "xlabel": "The local x-axis label", # add local subplot y-axis label "ylabel": "The local y-axis label", }, ], "title": "Title", "figsize": FIG_SIZE.A4_NARROW, "show_grid": SHOW_GRID.BOTH, "subplots": True, "sharex": True, "sharey": True, # show the confidence interval using the error values "show_yerr": True, } )

Additional Features¶

Axis scales¶

The user can change the axis scale using the scalex and scaley attributes. The supported scale options are:

Options	Description
"linear"	The linear scale.
"log"	The log scale.
"symlog"	The symmetric log scale.
"asinh"	The asinh scale.

Again, to help with the options settings, the datachart.constants module contains the following constants:

Constant	Description
datachart.constants.SCALE	The axis options.

In [18]:

from datachart.constants import SCALE

from datachart.constants import SCALE

To showcase the supported scales, we iterate through all of the scales options.

In [19]:

charts = {
    "data": [{"x": x / 10, "y": 1 + np.cos(x / 2)} for x in range(1, 21)],
}

charts = { "data": [{"x": x / 10, "y": 1 + np.cos(x / 2)} for x in range(1, 21)], }

In [20]:

for scale in [SCALE.LINEAR, SCALE.LOG, SCALE.SYMLOG, SCALE.ASINH]:
    figure = LineChart(
        {
            "charts": charts,
            "title": f"Graph showcasing the '{scale}' scale",
            "xlabel": "the global x-axis label",
            "ylabel": "the global y-axis label",
            "figsize": FIG_SIZE.A4_NARROW,
            "show_grid": SHOW_GRID.BOTH,
            # set the scale of the x and y axes
            "scalex": scale,
            "scaley": scale,
        }
    )

for scale in [SCALE.LINEAR, SCALE.LOG, SCALE.SYMLOG, SCALE.ASINH]: figure = LineChart( { "charts": charts, "title": f"Graph showcasing the '{scale}' scale", "xlabel": "the global x-axis label", "ylabel": "the global y-axis label", "figsize": FIG_SIZE.A4_NARROW, "show_grid": SHOW_GRID.BOTH, # set the scale of the x and y axes "scalex": scale, "scaley": scale, } )

Saving the Chart as an Image¶

To save the chart as an image, use the datachart.utils.save_figure function.

In [21]:

from datachart.utils import save_figure

from datachart.utils import save_figure

In [22]:

save_figure(figure, "./fig_line_chart.png", dpi=300)

save_figure(figure, "./fig_line_chart.png", dpi=300)

The figure should be saved in the current working directory.

Example Use Cases¶

Example 1: ROC curve¶

The example below shows how to create a ROC curve.

data attribute naming convention

By default, the charts["data"] items should be dictionaries with the following keys: x, y, yerr. However, they can be any other keys. In the example below, the charts["data"] contains the attributes tp and fp. To let the function know which values are which, you can specify the x and y attributes in the charts dictionary. This way, the function will know which value to use for the x- and y-axis.

In [23]:

from datachart.constants import HATCH_STYLE

from datachart.constants import HATCH_STYLE

In [24]:

_ = LineChart(
    {
        "charts": [
            {
                "data": [
                    # note that the attributes are "tp" and "fp", instead of "x" and "y"
                    {"tp": 0, "fp": 0},
                    {"tp": 0.1, "fp": 0},
                    {"tp": 0.1, "fp": 0.1},
                    {"tp": 0.3, "fp": 0.1},
                    {"tp": 0.3, "fp": 0.2},
                    {"tp": 0.5, "fp": 0.2},
                    {"tp": 0.5, "fp": 0.3},
                    {"tp": 0.8, "fp": 0.3},
                    {"tp": 0.8, "fp": 0.5},
                    {"tp": 1.0, "fp": 0.5},
                    {"tp": 1.0, "fp": 1.0},
                ],
                "subtitle": "Method 1",
                # specify which attr to use for x
                "x": "fp",
                # specify which attr to use for y
                "y": "tp",
                "style": {
                    "plot_area_hatch": HATCH_STYLE.DIAGONAL,
                },
            },
            {
                "data": [
                    # note that the attributes are "tp" and "fp", instead of "x" and "y"
                    {"tp": 0, "fp": 0},
                    {"tp": 0.2, "fp": 0},
                    {"tp": 0.2, "fp": 0.05},
                    {"tp": 0.8, "fp": 0.05},
                    {"tp": 0.8, "fp": 0.1},
                    {"tp": 1.0, "fp": 0.1},
                    {"tp": 1.0, "fp": 1.0},
                ],
                "subtitle": "Method 2",
                # specify which attr to use for x
                "x": "fp",
                # specify which attr to use for y
                "y": "tp",
                "style": {
                    "plot_area_hatch": HATCH_STYLE.DIAGONAL,
                },
            },
        ],
        "title": "AUC",
        "xlabel": "False Positive Rate",
        "ylabel": "True Positive Rate",
        "figsize": (5, 2.8),
        "show_grid": SHOW_GRID.BOTH,
        "xmin": 0,  # the minimum value of the x-axis
        "xmax": 1,  # the maximum value of the x-axis
        "ymin": 0,  # the minimum value of the y-axis
        "ymax": 1,  # the maximum value of the y-axis
        "show_area": True,
        "subplots": True,
        "sharex": True,
        "sharey": True,
        # assign the aspect ratio of all subplots
        "aspect_ratio": "equal",
    }
)

_ = LineChart( { "charts": [ { "data": [ # note that the attributes are "tp" and "fp", instead of "x" and "y" {"tp": 0, "fp": 0}, {"tp": 0.1, "fp": 0}, {"tp": 0.1, "fp": 0.1}, {"tp": 0.3, "fp": 0.1}, {"tp": 0.3, "fp": 0.2}, {"tp": 0.5, "fp": 0.2}, {"tp": 0.5, "fp": 0.3}, {"tp": 0.8, "fp": 0.3}, {"tp": 0.8, "fp": 0.5}, {"tp": 1.0, "fp": 0.5}, {"tp": 1.0, "fp": 1.0}, ], "subtitle": "Method 1", # specify which attr to use for x "x": "fp", # specify which attr to use for y "y": "tp", "style": { "plot_area_hatch": HATCH_STYLE.DIAGONAL, }, }, { "data": [ # note that the attributes are "tp" and "fp", instead of "x" and "y" {"tp": 0, "fp": 0}, {"tp": 0.2, "fp": 0}, {"tp": 0.2, "fp": 0.05}, {"tp": 0.8, "fp": 0.05}, {"tp": 0.8, "fp": 0.1}, {"tp": 1.0, "fp": 0.1}, {"tp": 1.0, "fp": 1.0}, ], "subtitle": "Method 2", # specify which attr to use for x "x": "fp", # specify which attr to use for y "y": "tp", "style": { "plot_area_hatch": HATCH_STYLE.DIAGONAL, }, }, ], "title": "AUC", "xlabel": "False Positive Rate", "ylabel": "True Positive Rate", "figsize": (5, 2.8), "show_grid": SHOW_GRID.BOTH, "xmin": 0, # the minimum value of the x-axis "xmax": 1, # the maximum value of the x-axis "ymin": 0, # the minimum value of the y-axis "ymax": 1, # the maximum value of the y-axis "show_area": True, "subplots": True, "sharex": True, "sharey": True, # assign the aspect ratio of all subplots "aspect_ratio": "equal", } )

Example 2: Training loss¶

The following example shows how to create a training loss chart.

data attribute naming convention

By default, the charts["data"] items should be dictionaries with the following keys: x, y, yerr. However, they can be any other keys. In the example below, the charts["data"] contains the attributes step and loss. To let the function know which values are which, you can specify the x and y attributes in the charts dictionary. This way, the function will know which value to use for the x- and y-axis.

Let us first update the global config:

In [25]:

from datachart.constants import COLORS
from datachart.config import config

from datachart.constants import COLORS from datachart.config import config

In [26]:

config.update_config(config={"color_general_multiple": COLORS.MixedDark})

config.update_config(config={"color_general_multiple": COLORS.MixedDark})

In [27]:

_ = LineChart(
    {
        "charts": [
            {
                "data": [
                    # note that the attributes are "step" and "loss", instead of "x" and "y"
                    {"step": step, "loss": (0.5 + random.random()) ** step}
                    for step in range(100)
                ],
                # specify which attr to use for x
                "x": "step",
                # specify which attr to use for y
                "y": "loss",
                "subtitle": "Method 1",
            },
            {
                "data": [
                    # note that the attributes are "step" and "loss", instead of "x" and "y"
                    {"step": step, "loss": (0.3 + random.random()) ** step}
                    for step in range(100)
                ],
                # specify which attr to use for x
                "x": "step",
                # specify which attr to use for y
                "y": "loss",
                "subtitle": "Method 2",
            },
            {
                "data": [
                    {"step": step, "loss": (0.2 + random.random()) ** step}
                    for step in range(100)
                ],
                # specify which attr to use for x
                "x": "step",
                # specify which attr to use for y
                "y": "loss",
                "subtitle": "Method 3",
            },
        ],
        "title": "Training Performance",
        "xlabel": "training steps",
        "ylabel": "training loss",
        "figsize": FIG_SIZE.A4_NARROW,
        "show_grid": SHOW_GRID.Y,
        "show_legend": True,
        # depict the y-axis as a log scale
        "scaley": "log",
        "subplots": False,
    }
)

_ = LineChart( { "charts": [ { "data": [ # note that the attributes are "step" and "loss", instead of "x" and "y" {"step": step, "loss": (0.5 + random.random()) ** step} for step in range(100) ], # specify which attr to use for x "x": "step", # specify which attr to use for y "y": "loss", "subtitle": "Method 1", }, { "data": [ # note that the attributes are "step" and "loss", instead of "x" and "y" {"step": step, "loss": (0.3 + random.random()) ** step} for step in range(100) ], # specify which attr to use for x "x": "step", # specify which attr to use for y "y": "loss", "subtitle": "Method 2", }, { "data": [ {"step": step, "loss": (0.2 + random.random()) ** step} for step in range(100) ], # specify which attr to use for x "x": "step", # specify which attr to use for y "y": "loss", "subtitle": "Method 3", }, ], "title": "Training Performance", "xlabel": "training steps", "ylabel": "training loss", "figsize": FIG_SIZE.A4_NARROW, "show_grid": SHOW_GRID.Y, "show_legend": True, # depict the y-axis as a log scale "scaley": "log", "subplots": False, } )