27.17.5 Heatmap

Heat Map-01.png

Data Requirements

  • Worksheet: Select XY columns or XYZ columns (full or subrange); or a virtual matrix.

or

  • Matrix: A matrix of Z values.

Creating the Graph

Activate the matrix sheet or select required data from worksheet.

From the menu, choose Plot > Contour: Heatmap.

or

Click the Heatmap button on the 3D and Contour Graphs toolbar.

Heat Map-02.png

Template

HeatMap.otp

(Installed to the Origin program folder).

Notes

This graph is based on the contour plot but has some differences:

  • On the graph's Plot Details Colormap/Contours tab, Fill to Grid Lines is enabled by default; No contour lines are drawn.
  • Ticks are centered on the block. No minor ticks are shown.
  • When plotting from XY worksheet data, a 2D frequency count is performed on XY data, based on user-specified input. By default, bins are automatically chosen and a count of XY pairs is assigned to each bin. The resulting binned output is used to generate the heatmap, with bin centers in output sheet label rows supplying Y axis ticks/labels and bin centers in the first column supplying X axis ticks/labels. Binning is handled by the plot_heatmapxy X-Function.
  • When plotting from XYZ worksheet data, a 2D frequency count is performed on XYZ data, based on user-specified input. By default, bins are automatically chosen and a mean Z value is calculated for each bin (note that the user can specify other statistics). The resulting binned output is used to generate the heatmap, with bin centers in output sheet label rows supplying Y axis ticks/labels and bin centers in the first column supplying X axis ticks/labels. Binning is handled by the plot_heatmapxyz X-Function.
  • When plotting from a virtual matrix, the number of major ticks on the x axis will equal the number of rows; the number of major ticks on the y axis will equal the number of columns.
  • By default, the heatmap plots using the Thermometer palette for the Colormap Fill. Missing values use a deeper blue color than the color for 0.