++ed by:

5 PAUSE users
4 non-PAUSE users.

Pablo Rodríguez
and 3 contributors

# NAME

Chart::Plotly::Trace::Heatmap - The data that describes the heatmap value-to-color mapping is set in `z`. Data in `z` can either be a {2D array} of values (ragged or not) or a 1D array of values. In the case where `z` is a {2D array}, say that `z` has N rows and M columns. Then, by default, the resulting heatmap will have N partitions along the y axis and M partitions along the x axis. In other words, the i-th row/ j-th column cell in `z` is mapped to the i-th partition of the y axis (starting from the bottom of the plot) and the j-th partition of the x-axis (starting from the left of the plot). This behavior can be flipped by using `transpose`. Moreover, `x` (`y`) can be provided with M or M+1 (N or N+1) elements. If M (N), then the coordinates correspond to the center of the heatmap cells and the cells have equal width. If M+1 (N+1), then the coordinates correspond to the edges of the heatmap cells. In the case where `z` is a 1D {array}, the x and y coordinates must be provided in `x` and `y` respectively to form data triplets.

version 0.037

# SYNOPSIS

`````` use Chart::Plotly qw(show_plot);
use Chart::Plotly::Trace::Heatmap;
use English qw(-no_match_vars);

my \$heatmap = Chart::Plotly::Trace::Heatmap->new(
x => [ 0 .. 10 ],
y => [ 0 .. 10 ],
z => [
map {
my \$y = \$ARG;
[ map { \$ARG * \$ARG + \$y * \$y } ( 0 .. 10 ) ]
} ( 0 .. 10 )
]
);

show_plot( [\$heatmap] );``````

# DESCRIPTION

The data that describes the heatmap value-to-color mapping is set in `z`. Data in `z` can either be a {2D array} of values (ragged or not) or a 1D array of values. In the case where `z` is a {2D array}, say that `z` has N rows and M columns. Then, by default, the resulting heatmap will have N partitions along the y axis and M partitions along the x axis. In other words, the i-th row/ j-th column cell in `z` is mapped to the i-th partition of the y axis (starting from the bottom of the plot) and the j-th partition of the x-axis (starting from the left of the plot). This behavior can be flipped by using `transpose`. Moreover, `x` (`y`) can be provided with M or M+1 (N or N+1) elements. If M (N), then the coordinates correspond to the center of the heatmap cells and the cells have equal width. If M+1 (N+1), then the coordinates correspond to the edges of the heatmap cells. In the case where `z` is a 1D {array}, the x and y coordinates must be provided in `x` and `y` respectively to form data triplets.

Screenshot of the above example:

This file has been autogenerated from the official plotly.js source.

If you like Plotly, please support them: https://plot.ly/ Open source announcement: https://plot.ly/javascript/open-source-announcement/

Full reference: https://plot.ly/javascript/reference/#heatmap

# DISCLAIMER

This is an unofficial Plotly Perl module. Currently I'm not affiliated in any way with Plotly. But I think plotly.js is a great library and I want to use it with perl.

# METHODS

## TO_JSON

Serialize the trace to JSON. This method should be called only by JSON serializer.

Trace type.

# ATTRIBUTES

• autocolorscale

Determines whether the colorscale is a default palette (`autocolorscale: true`) or the palette determined by `colorscale`. In case `colorscale` is unspecified or `autocolorscale` is true, the default palette will be chosen according to whether numbers in the `color` array are all positive, all negative or mixed.

• coloraxis

Sets a reference to a shared color axis. References to these shared color axes are *coloraxis*, *coloraxis2*, *coloraxis3*, etc. Settings for these shared color axes are set in the layout, under `layout.coloraxis`, `layout.coloraxis2`, etc. Note that multiple color scales can be linked to the same color axis.

• colorbar

• colorscale

Sets the colorscale. The colorscale must be an array containing arrays mapping a normalized value to an rgb, rgba, hex, hsl, hsv, or named color string. At minimum, a mapping for the lowest (0) and highest (1) values are required. For example, `[[0, 'rgb(0,0,255)'], [1, 'rgb(255,0,0)']]`. To control the bounds of the colorscale in color space, use`zmin` and `zmax`. Alternatively, `colorscale` may be a palette name string of the following list: Greys,YlGnBu,Greens,YlOrRd,Bluered,RdBu,Reds,Blues,Picnic,Rainbow,Portland,Jet,Hot,Blackbody,Earth,Electric,Viridis,Cividis.

• connectgaps

Determines whether or not gaps (i.e. {nan} or missing values) in the `z` data are filled in. It is defaulted to true if `z` is a one dimensional array and `zsmooth` is not false; otherwise it is defaulted to false.

• customdata

Assigns extra data each datum. This may be useful when listening to hover, click and selection events. Note that, *scatter* traces also appends customdata items in the markers DOM elements

• customdatasrc

Sets the source reference on plot.ly for customdata .

• dx

• dy

• hoverinfo

Determines which trace information appear on hover. If `none` or `skip` are set, no information is displayed upon hovering. But, if `none` is set, click and hover events are still fired.

• hoverinfosrc

Sets the source reference on plot.ly for hoverinfo .

• hoverlabel

• hoverongaps

Determines whether or not gaps (i.e. {nan} or missing values) in the `z` data have hover labels associated with them.

• hovertemplate

Template string used for rendering the information that appear on hover box. Note that this will override `hoverinfo`. Variables are inserted using %{variable}, for example "y: %{y}". Numbers are formatted using d3-format's syntax %{variable:d3-format}, for example "Price: %{y:\$.2f}". https://github.com/d3/d3-3.x-api-reference/blob/master/Formatting.md#d3_format for details on the formatting syntax. Dates are formatted using d3-time-format's syntax %{variable|d3-time-format}, for example "Day: %{2019-01-01|%A}". https://github.com/d3/d3-3.x-api-reference/blob/master/Time-Formatting.md#format for details on the date formatting syntax. The variables available in `hovertemplate` are the ones emitted as event data described at this link https://plot.ly/javascript/plotlyjs-events/#event-data. Additionally, every attributes that can be specified per-point (the ones that are `arrayOk: true`) are available. Anything contained in tag `<extra>` is displayed in the secondary box, for example "<extra>{fullData.name}</extra>". To hide the secondary box completely, use an empty tag `<extra></extra>`.

• hovertemplatesrc

Sets the source reference on plot.ly for hovertemplate .

• hovertext

Same as `text`.

• hovertextsrc

Sets the source reference on plot.ly for hovertext .

• ids

Assigns id labels to each datum. These ids for object constancy of data points during animation. Should be an array of strings, not numbers or any other type.

• idssrc

Sets the source reference on plot.ly for ids .

• legendgroup

Sets the legend group for this trace. Traces part of the same legend group hide/show at the same time when toggling legend items.

• pmeta

Assigns extra meta information associated with this trace that can be used in various text attributes. Attributes such as trace `name`, graph, axis and colorbar `title.text`, annotation `text` `rangeselector`, `updatemenues` and `sliders` `label` text all support `meta`. To access the trace `meta` values in an attribute in the same trace, simply use `%{meta[i]}` where `i` is the index or key of the `meta` item in question. To access trace `meta` in layout attributes, use `%{data[n[.meta[i]}` where `i` is the index or key of the `meta` and `n` is the trace index.

• metasrc

Sets the source reference on plot.ly for meta .

• name

Sets the trace name. The trace name appear as the legend item and on hover.

• opacity

Sets the opacity of the trace.

• reversescale

Reverses the color mapping if true. If true, `zmin` will correspond to the last color in the array and `zmax` will correspond to the first color.

• showlegend

Determines whether or not an item corresponding to this trace is shown in the legend.

• showscale

Determines whether or not a colorbar is displayed for this trace.

• stream

• text

Sets the text elements associated with each z value.

• textsrc

Sets the source reference on plot.ly for text .

• transforms

• transpose

Transposes the z data.

• uid

Assign an id to this trace, Use this to provide object constancy between traces during animations and transitions.

• uirevision

Controls persistence of some user-driven changes to the trace: `constraintrange` in `parcoords` traces, as well as some `editable: true` modifications such as `name` and `colorbar.title`. Defaults to `layout.uirevision`. Note that other user-driven trace attribute changes are controlled by `layout` attributes: `trace.visible` is controlled by `layout.legend.uirevision`, `selectedpoints` is controlled by `layout.selectionrevision`, and `colorbar.(x|y)` (accessible with `config: {editable: true}`) is controlled by `layout.editrevision`. Trace changes are tracked by `uid`, which only falls back on trace index if no `uid` is provided. So if your app can add/remove traces before the end of the `data` array, such that the same trace has a different index, you can still preserve user-driven changes if you give each trace a `uid` that stays with it as it moves.

• visible

Determines whether or not this trace is visible. If *legendonly*, the trace is not drawn, but can appear as a legend item (provided that the legend itself is visible).

• x

Sets the x coordinates.

• x0

Alternate to `x`. Builds a linear space of x coordinates. Use with `dx` where `x0` is the starting coordinate and `dx` the step.

• xaxis

Sets a reference between this trace's x coordinates and a 2D cartesian x axis. If *x* (the default value), the x coordinates refer to `layout.xaxis`. If *x2*, the x coordinates refer to `layout.xaxis2`, and so on.

• xcalendar

Sets the calendar system to use with `x` date data.

• xgap

Sets the horizontal gap (in pixels) between bricks.

• xsrc

Sets the source reference on plot.ly for x .

• xtype

If *array*, the heatmap's x coordinates are given by *x* (the default behavior when `x` is provided). If *scaled*, the heatmap's x coordinates are given by *x0* and *dx* (the default behavior when `x` is not provided).

• y

Sets the y coordinates.

• y0

Alternate to `y`. Builds a linear space of y coordinates. Use with `dy` where `y0` is the starting coordinate and `dy` the step.

• yaxis

Sets a reference between this trace's y coordinates and a 2D cartesian y axis. If *y* (the default value), the y coordinates refer to `layout.yaxis`. If *y2*, the y coordinates refer to `layout.yaxis2`, and so on.

• ycalendar

Sets the calendar system to use with `y` date data.

• ygap

Sets the vertical gap (in pixels) between bricks.

• ysrc

Sets the source reference on plot.ly for y .

• ytype

If *array*, the heatmap's y coordinates are given by *y* (the default behavior when `y` is provided) If *scaled*, the heatmap's y coordinates are given by *y0* and *dy* (the default behavior when `y` is not provided)

• z

Sets the z data.

• zauto

Determines whether or not the color domain is computed with respect to the input data (here in `z`) or the bounds set in `zmin` and `zmax` Defaults to `false` when `zmin` and `zmax` are set by the user.

• zhoverformat

Sets the hover text formatting rule using d3 formatting mini-languages which are very similar to those in Python. See: https://github.com/d3/d3-3.x-api-reference/blob/master/Formatting.md#d3_format

• zmax

Sets the upper bound of the color domain. Value should have the same units as in `z` and if set, `zmin` must be set as well.

• zmid

Sets the mid-point of the color domain by scaling `zmin` and/or `zmax` to be equidistant to this point. Value should have the same units as in `z`. Has no effect when `zauto` is `false`.

• zmin

Sets the lower bound of the color domain. Value should have the same units as in `z` and if set, `zmax` must be set as well.

• zsmooth

Picks a smoothing algorithm use to smooth `z` data.

• zsrc

Sets the source reference on plot.ly for z .

# AUTHOR

Pablo Rodríguez González <pablo.rodriguez.gonzalez@gmail.com>

``  The MIT (X11) License``