Plotting

This page covers plotting the Graph object in various matrix forms using the ragraph.plot module. In particular we will focus on the ragraph.plot.mdm function and the ragraph.plot.Style object. The mdm function can be used to quickly generate multi-domain-matrix (MDM) and dependency-structure-matrix (DSM) figures of your data set. The Style object allows one to filter the information to be displayed and set the appearance of the figure.

The Ford Climate Control System dataset is used to illustrate the various plot options.

Basic plotting

To create a plot, first the import the module and use the plot function as follows:

from ragraph import datasets, plot

g = datasets.get("climate_control")
fig = plot.mdm(
    leafs=g.leafs,
    edges=g.edges,
)
fig.write_image("docs/generated/mdm_edge_kinds.svg")

The mdm function requires two arguments: leafs, which is the list of nodes to be displayed on the rows and columns of the matrix, and edges, which is the list of edges (dependencies) to be displayed within the matrix. The figure can be saved to file using the fig.write_image(filename) function by Plotly.

The figure below shows the resulting matrix. By default, the different edge kinds are displayed within the matrix. In this case, the dataset only contains the edge kind edge, as shown within the legend at the bottom right of the figure.

Product DSM of the climate control system showing dependencykinds.

Note that the leafs are automatically sorted following the hierarchical structure found within the graph. If one would like to display the leafs within the order as provided, one can pass along the argument sort=False to the mdm function.

In case one wants to create a non-square matrix or a matrix with different nodes on the rows than on the columns. One can use the Domain Mapping Matrix ragraph.plot.dmm function:

from ragraph import datasets, plot

g = datasets.get("climate_control")
rows = g.leafs[0:6]
cols = g.leafs

fig = plot.dmm(
    rows=rows,
    cols=cols,
    edges=[e for e in g.edges_between_all(sources=cols, targets=rows)],
    sort=False,
)
fig.write_image("./docs/generated/dmm_example.svg")

This results in the figure below, in which we now have more columns than rows.

Mapping matrix of the climate control system.

Tuning the axis nodes

A big part of your figures content is the ordering of leaf nodes on the axis. By default the leaf nodes you provide will be sorted according to:

1. The hierarchy they are subject to.
2. The node kind they belong to.
3. Whether or not they are a bus node.
4. How big their "width" is in terms of leaf nodes (e.g. biggest clusters first).

You can tweak this behavior like so:

from ragraph import datasets, plot

g = datasets.get("climate_control")

fig = plot.mdm(
    leafs=g.leafs,
    edges=g.edges,
    node_kinds=["node"],  # You can order and filter node kinds here.
    sort_args=dict(
        sort_by_bus=False,  # Don't actively put bus nodes first.
        sort_by_width=False,  # Don't put wider (larger) nodes first.
    ),
)
fig.write_image('./docs/generated/mdm_tweaked_sort.svg')

MDM figure with automatic sorting tweaked to only reflect the hierarchy and no further optimizations.

Where sort_args are options to be passed to ragraph.analysis.sequence.axis.

Or you can also disable this behavior altogether and plot the (leaf) nodes as given:

from ragraph import datasets, plot

g = datasets.get("climate_control")

fig = plot.mdm(
    leafs=g.leafs,  # Custom ordering here.
    edges=g.edges,
    sort=False,
)
fig.write_image("./docs/generated/mdm_custom_sort.svg")

MDM figure with automatic sorting disabled. Sorting is fully custom as given in the leaf list.

Information filtering

The Graph may contain Edge objects of various kinds to which various labels and weights are attached. By passing along a Style object to the style argument of the mdm function one can set the information that is displayed within the matrix.

In the snippet below, the value of the display key of the piemap property of the Style object is set to be equal to "weight labels".

The snippet and corresponding figure below show the resulting matrix in which the labels of the different weights attached to the edges are displayed as categories within a pie chart.

from ragraph import datasets, plot

g = datasets.get("climate_control")

fig = plot.mdm(
    leafs=g.leafs,
    edges=g.edges,
    style=plot.Style(piemap=dict(display="weight labels")),
)
fig.write_image("./docs/generated/mdm_edge_weight_labels.svg")

Product DSM of the climate control system showing all edge weight labels.

By changing the value of display to "weights" the matrix changes from a categorical plot to a numerical plot as shown in the next figure. Here the actual numerical values of the different weights are shown rather than the weight labels.

from ragraph import datasets, plot

g = datasets.get("climate_control")

fig = plot.mdm(
    leafs=g.leafs,
    edges=g.edges,
    style=plot.Style(
        piemap=dict(
            display="weights",
        )
    ),
)
fig.write_image("./docs/generated/mdm_edge_weights_1.svg")

Product DSM of the climate control system showing edge weights.

By default, all elements that belong to the display category are shown. One can change this by setting the fields key of the piemap dictionary as shown in the following snippet, which yields the figure right after it. Here only the numerical values of the weights "spatial", "energy flow", and "information flow" are displayed.

from ragraph import datasets, plot

g = datasets.get("climate_control")

fig = plot.mdm(
    leafs=g.leafs,
    edges=g.edges,
    style=plot.Style(
        piemap=dict(
            display="weights",
            fields=[
                "spatial",
                "energy flow",
                "information flow",
            ],
        )
    ),
)
fig.write_image("./docs/generated/mdm_edge_weights_2.svg")

Product DSM of the climate control system showing a subset of edge weights.

In all figures shown so far, the wedges displayed within the pie charts are of equal size. You can change this by setting the value of the mode key of the piemap dictionary to "relative". As a result, the size of the wedges is scaled following the numerical value attached to it as shown in the following:

from ragraph import datasets, plot

g = datasets.get("climate_control")

fig = plot.mdm(
    leafs=g.leafs,
    edges=g.edges,
    style=plot.Style(
        piemap=dict(
            display="weights",
            fields=[
                "spatial",
                "energy flow",
                "information flow",
            ],
            mode="relative",
        )
    ),
)
fig.write_image("./docs/generated/mdm_edge_weights_3.svg")

Product DSM of the climate control system showing relative wedge sizes.

The examples shown in this section are far from exhaustive. Check out the ragraph.plot.generic.PieMapStyle documentation for all properties that one can set within the piemap dictionary.

Information highlighting

Highlighting certain rows and columns is possible as well. By default, you can highlight rows and columns by setting the highlight annotation to True on a Node instance:

from ragraph import datasets, plot

g = datasets.get("climate_control")

g["Accumulator"].annotations.highlight = True
g["Compressor"].annotations.highlight = "rgba(255,0,0,0.25)"

fig = plot.mdm(leafs=g.leafs, edges=g.edges)
fig.write_image("./docs/generated/mdm_highlight.svg")

Product DSM of the climate control system highlighting the Accumulator and Compressor.

You can override certain settings via the Style object, too:

from ragraph import datasets, plot

g = datasets.get("climate_control")

style = plot.Style(
    highlight_annotation="highlight",
    highlight_color="rgba(0,255,0,0.5)",
    piemap=dict(
        highlight_row_annotation="row",
        highlight_row_color="rgba(255,0,0,0.5)",
        highlight_col_annotation=None,
        highlight_col_color=None,
    ),
)

g["Accumulator"].annotations.row = "rgba(0,0,255,0.25)"
g["Command Distribution"].annotations.row = True
g["Compressor"].annotations.highlight = True

fig = plot.mdm(
    leafs=g.leafs,
    edges=g.edges,
    style=style,
)
fig.write_image("./docs/generated/mdm_highlight_custom.svg")

Product DSM of the climate control system showcasing all highlighting options.

That's a lot of overrides fighting for precedence! In short, when you override the highlight_row_annotation or highlight_col_annotation keys in the piemap specific options, the PieMap's highlighting of rows or columns will only look for those annotation keys in row or column Nodes (e.g. the default one is completely ignored). If these override are unset or None, it will look for the global highlight annotation key. So:

1. ragraph.plot.generic.PieMapStyle's row/column annotation key is considered.
2. Only if there is no style entry for that, the ragraph.plot.generic.Style highlight key is considered.

Secondly, the color's precedence is always:

1. Annotation key's value if it's a string.
2. ragraph.plot.generic.PieMapStyle row/column override color if set.
3. ragraph.plot.generic.Style default highlight color.

Matrix styling

The colors of the fields displayed within the matrix are automatically generated. However, for easy comparison of multiple plots one may want to explicitly set the color, or color map of a field.

In the snippet below the the color of the displayed weight labels are explicitly set by setting the value of the fields key within the palettes property of the Style object. Here one can provide a dictionary mapping weight labels to color hex codes. The result of setting these colors is shown in the following snippet and figure:

from ragraph import datasets, plot

g = datasets.get("climate_control")

fig = plot.mdm(
    leafs=g.leafs,
    edges=g.edges,
    style=plot.Style(
        piemap=dict(
            display="weight labels",
            fields=[
                "spatial",
                "energy flow",
                "information flow",
                "material flow",
            ],
        ),
        palettes=dict(
            fields={
                "spatial": {"categorical": "#a64747"},
                "energy flow": {"categorical": "#de9c38"},
                "information flow": {"categorical": "#148a8e"},
                "material flow": {"categorical": "#b8bd6c"},
            }
        ),
    ),
)
fig.write_image("./docs/generated/mdm_edge_categorical_field_colors.svg")

Product DSM of the climate control system showing edge weight labels with user defined colors.

Similarly, one can set the colors for numerical values. Here one has to provide a list of colors (a color map). The ragraph.colors module provides several functions for generating such color maps.

In the example below, the functions get_diverging_redblue, get_diverging_orangecyan, and get_diverging_purplegreen are used to set a diverging color map for the displayed weights in the next figure.

from ragraph import datasets, plot
from ragraph.colors import (
    get_diverging_redblue,
    get_diverging_orangecyan,
    get_diverging_purplegreen,
)

g = datasets.get("climate_control")

fig = plot.mdm(
    leafs=g.leafs,
    edges=g.edges,
    style=plot.Style(
        piemap=dict(
            display="weights",
            fields=[
                "spatial",
                "energy flow",
                "information flow",
            ],
        ),
        palettes=dict(
            fields={
                "spatial": {"continuous": get_diverging_redblue()},
                "energy flow": {"continuous": get_diverging_orangecyan()},
                "information flow": {"continuous": get_diverging_purplegreen()},
            }
        ),
    ),
)
fig.write_image("./docs/generated/mdm_edge_continuous_field_colors.svg")

Product DSM of the climate control system showing edge weight labels with user defined color gradients.

Check out the documentation of the ragraph.plot.generic.Palettes object to check all options that can be set using the pallettes argument.

Basic customization

The DSM literature presents a create variety of matrix based visualizations. These visualizations often differ with respect to the information displayed within the matrix. The ragraph.plot module is built upon the open source Plotly library. As such, one customize the generated figures.

In the snippet below numbers and squares are added to the diagonal of the matrix. The numbers are added by adding a scatter trace to the figure using the add_trace method.

import plotly.graph_objs as go
from ragraph.colors import get_green
from ragraph import datasets, plot

g = datasets.get("climate_control")

fig = plot.mdm(
    leafs=g.leafs,
    edges=g.edges,
    style=plot.Style(piemap=dict(display="kinds")),
)
# Coordinates and colors for custom traces and shapes.
n_nodes = len(g.leafs)
x = [idx + 0.5 for idx in range(n_nodes)]
y = [n_nodes - 0.5 - idy for idy in range(n_nodes)]
colors = get_green(n_nodes)
# Create and add trace for numbers on diagonal.
text_trace = go.Scatter(
    x=x,
    y=y,
    text=[str(idx + 1) for idx in range(n_nodes)],
    mode="text",
    showlegend=False,
)
fig = fig.add_trace(text_trace, row=2, col=4)
# Create and add shapes for colored squares on diagonal.
shapes = []
for idx, color in enumerate(colors):
    shapes.append(
        go.layout.Shape(
            type="rect",
            x0=x[idx] - 0.5,
            y0=y[idx] + 0.5,
            x1=x[idx] + 0.5,
            y1=y[idx] - 0.5,
            fillcolor=color,
            xref="x9",
            yref="y9",
            layer="below",
        )
    )
fig = fig.update_layout(shapes=list(fig.layout.shapes) + shapes)
fig.write_image("./docs/generated/mdm_custom.svg")

Product DSM of the climate control system showing edge kinds with a custom color gradient and numbers on the diagonal.

Note the row and col arguments of the add_trace method. The plot consists of six components which are instances of the Tree, Labels, PieMap, and Legend objects. These components are placed within a grid containing two rows and five columns. By setting the row and col arguments one can add the trace to one of the six plot components.

The squares are added by using the update_layout method to update the shapes property of the figure. In creating the figure shapes, the arguments xref and yref are set to x9 and y9, respectively. This ensures that the shapes are positioned with respect to x-axis nine and y-axis nine. In this case, being the axes of the matrix (piemap).

Advanced customization

One can take customization one step further. As the plot components are placed within a grid, one can expand the grid with additional rows and columns filled with custom components.

The snippet below shows a custom plot component class ColorBar, which inherits its properties from the ragraph.plot.generic.Component class which is the basic building block for creating compound Plotly figures.

from ragraph import datasets
from ragraph.plot.generic import Component, Style
from ragraph.node import Node
from ragraph.edge import Edge
from ragraph.plot import utils, components
from ragraph.colors import (
    get_red,
    get_green,
    get_orange,
    get_blue,
)
from plotly import graph_objs as go
from typing import List, Optional


class ColorBar(Component):
    """Color bar plot component.
    Arguments:
      leafs: The list of nodes on the axis of the matrix.
      colors: The list of colors to be used in the color bar
              (len(colors >= len(leafs))).
      orientation: One of "horizontal" or "vertical". Defaults to vertical
      Style: Style object of the plot.
    """

    def __init__(
        self,
        leafs: List[Node],
        colors: List[str],
        orientation: str = "vertical",
        style: Style = Style(),
    ):
        # Calculating shape coordinates
        shapes = []
        for idx in range(len(leafs)):
            if orientation == "vertical":
                x0 = 0
                x1 = style.xstep
                y0 = idx * style.ystep
                y1 = (idx + 1) * style.ystep
            elif orientation == "horizontal":
                x0 = idx * style.xstep
                x1 = (idx + 1) * style.xstep
                y0 = 0
                y1 = style.ystep
            shapes.append(
                go.layout.Shape(
                    type="rect",
                    x0=x0,
                    y0=y0,
                    x1=x1,
                    y1=y1,
                    fillcolor=colors[idx],
                )
            )
        # Calculating geometric boundaries.
        if orientation == "vertical":
            width = (style.xstep) * style.boxsize
            height = len(leafs) * style.ystep * style.boxsize
        elif orientation == "horizontal":
            width = len(leafs) * style.xstep * style.boxsize
            height = (style.ystep) * style.boxsize
        xaxis = go.layout.XAxis(
            automargin=False,
            scaleanchor="y",
            autorange=False,
            scaleratio=1.0,
            # showgrid=True,
            # showline=True,
            showticklabels=False,
            # zeroline=True,
            range=(0, width / style.boxsize),
        )
        yaxis = go.layout.YAxis(
            automargin=False,
            autorange=False,
            showgrid=True,
            # showline=True,
            showticklabels=False,
            # zeroline=True,
            range=(0, height / style.boxsize),
        )
        super().__init__(
            width=width,
            height=height,
            traces=[],
            shapes=shapes,
            xaxis=xaxis,
            yaxis=yaxis,
        )


def custom_mdm(
    leafs: List[Node],
    edges: List[Edge],
    style: Style = Style(),
    sort: Optional[bool] = True,
    node_kinds: Optional[List[str]] = None,
    show: Optional[bool] = False,
) -> go.Figure:
    """Get a custom plot of a Graph object."""
    if sort:
        leafs = utils.get_axis_sequence(leafs, kinds=node_kinds)
    first_row = [
        None,
        None,
        None,
        ColorBar(
            leafs=leafs,
            colors=get_red(len(leafs)),
            orientation="horizontal",
            style=style,
        ),
        None,
        None,
    ]
    second_row = [
        components.Tree(leafs, style=style),
        components.Labels(leafs, style=style),
        ColorBar(
            leafs=leafs,
            colors=get_green(len(leafs)),
            orientation="vertical",
            style=style,
        ),
        components.PieMap(rows=leafs, cols=leafs, edges=edges, style=style),
        ColorBar(
            leafs=leafs,
            colors=get_orange(len(leafs)),
            orientation="vertical",
            style=style,
        ),
        components.Legend(edges, style=style),
    ]
    third_row = [
        None,
        None,
        None,
        ColorBar(
            leafs=leafs,
            colors=get_blue(len(leafs)),
            orientation="horizontal",
            style=style,
        ),
        None,
        None,
    ]
    fig = utils.get_subplots([first_row, second_row, third_row])
    return utils.process_fig(fig=fig, show=show, style=style)


g = datasets.get("climate_control")
fig = custom_mdm(
    leafs=g.leafs,
    edges=g.edges,
    style=Style(
        piemap=dict(display="weight labels"),
    ),
)
fig.write_image("./docs/generated/mdm_custom_advanced.svg")

Product DSM of the climate control system showing edge weights labels with custom colorbars around the matrix.

The grid layout of this figure was defined within the custom_mdm method. The figure is composed of three rows and six columns. The first row contains a ColorBar component within the fourth column. All other positions are empty within. The second row contains six plot components: a Tree, Labels, a custom ColorBar, a PieMap, another ColorBar, and a Legend component. The third row only contains a ColorBar component in the right position.

With use of the functions Ragraph ragraph.plot.utils.get_subplots and ragraph.plot.utils.process_fig the plot components are joined into a single Plotly figure object.

Note

Matching the scaling of all figures within a grid plot can be quite tricky. The axis of neighboring plots are automatically linked. Hence one should take care when setting the range of the axis of custom plot components. The Style.xstep, Style.ystep, and Style.boxsize properties of the Style object are particularly important in matching the scaling of figures.