surface charts

I have attached 3 files:

a gnumeric file with a contour and a surface plot
a PNG showing the contour plot
a PNG showing the surface plot

In all three cases the data comes from the region:

   A  B  C  D
R1    1  2  3
R2 1  1  2  3
R3 2  1  4  9
R4 3  1  8  9

intended as a 3 by 3 surface with the height values contained in
Sheet1.$B$2:Sheet1.$D$4

Gnumeric stores the surface plot in an ODS file as 

    <office:chart>
      <chart:chart svg:width="152.00pt" svg:height="101.00pt" chart:class="chart:surface" chart:style-name="plotstyle">
        <chart:plot-area chart:style-name="plotarea" table:cell-range-address="Sheet1.$A$2:Sheet1.$A$4">
          <chart:axis chart:dimension="z" chart:style-name="zaxis"/>
          <chart:axis chart:dimension="y" chart:style-name="yaxis"/>
          <chart:axis chart:dimension="x" chart:style-name="zaxis"/>
          <chart:series chart:values-cell-range-address="Sheet1.$B$2:Sheet1.$D$4" chart:style-name="series1">
            <chart:domain table:cell-range-address="Sheet1.$A$2:Sheet1.$A$4"/>
            <chart:domain table:cell-range-address="Sheet1.$B$1:Sheet1.$D$1"/>
          </chart:series>
          <chart:wall svg:width="152.00pt" chart:style-name="wallstyle"/>
        </chart:plot-area>
      </chart:chart>
    </office:chart>

with

    <style:style style:name="plotstyle" style:family="chart">
      <style:chart-properties chart:auto-size="true" chart:three-dimensional="true"/>
    </style:style>


Similarly the contour chart is


    <office:chart>
      <chart:chart svg:width="152.00pt" svg:height="86.75pt" chart:class="chart:surface" chart:style-name="plotstyle">
        <chart:plot-area chart:style-name="plotarea" table:cell-range-address="Sheet1.$A$2:Sheet1.$A$4">
          <chart:axis chart:dimension="y" chart:style-name="yaxis"/>
          <chart:axis chart:dimension="x" chart:style-name="zaxis"/>
          <chart:series chart:values-cell-range-address="Sheet1.$B$2:Sheet1.$D$4" chart:style-name="series1">
            <chart:domain table:cell-range-address="Sheet1.$A$2:Sheet1.$A$4"/>
            <chart:domain table:cell-range-address="Sheet1.$B$1:Sheet1.$D$1"/>
          </chart:series>
          <chart:wall svg:width="152.00pt" chart:style-name="wallstyle"/>
        </chart:plot-area>
      </chart:chart>
    </office:chart>

with

    <style:style style:name="plotstyle" style:family="chart">
      <style:chart-properties chart:auto-size="true" chart:three-dimensional="false"/>
    </style:style>

Note that this way of storing surface plots would allow a program to add several surfaces to the same plot by adding multiple series. 

Andreas

  
-- 
Andreas J. Guelzow
Concordia University College of Alberta