2.2.4.8.32 DataPlot::SetColormap

Description

Set the Z levels for the colormap inside the data plot (applies to dataplot with colormaps, like contour plot) The 1st value in vz is the minimum Z value and the last value in vz the maximum, so vz must at least contain 2 values.

Syntax

BOOL SetColormap( TreeNode & trColormap )


BOOL SetColormap( const vector<double> & vz, BOOL bLogScale = FALSE )

Parameters

trColormap
[input] A TreeNode object with the Tree structure similar to the One obtained from GetColormap.


vz
[input]A Vector of Doubles, specifying the the z-level values to be set.
bLogScale
[input]bLogScale, TRUE will set the colormap levels scale to Logarithmic, FALSE for linear. It's no use in Origin 8.1 or later build because more scale types are added.

Return

TRUE for success and FALSE for failure.


TRUE for success and FALSE for failure. Returns FALSE if has negative in vz.

Examples

EX1

// assume active window has a contour plot, or any plot that supports colormap
void DataObject_SetColormap_ex1()
{
    int nLevels = 20;
    double z1 = -1.5, z2 = 1.5;

    GraphLayer gl = Project.ActiveLayer();
    DataPlot dp = gl.DataPlots(0);
    // setup z levels in percent
    // first value must be 0 and last value must be < 100
    vector vLevels;
    vLevels.Data(0, 100*(nLevels-1)/nLevels, 100./nLevels);
    // setup colors for each
    vector<uint> vColors;
    vColors.SetSize(nLevels);
    for(int ii = 0; ii < nLevels; ii++)
    {
        int gg = 255* ii / (nLevels-1);
        int bb = 255 * (nLevels-ii-1)/(nLevels-1);
        int nRGB = RGB(0, gg, bb);
        vColors[ii] = RGB2OCOLOR(nRGB);
    }
    // construct tree from scratch, you can also get the colormap tree by calling GetColormap, but then
    // you will have to match up all the vectors, so simpler to just create new tree with only the
    // settings that we need to change
    Tree tr;
    tr.ColorMap.Details.Levels.dVals = vLevels;
    tr.ColorMap.Details.BelowColor.nVal = SYSCOLOR_RED; 
    tr.ColorMap.Details.AboveColor.nVal = SYSCOLOR_PINK; 
    tr.ColorMap.Details.Colors.nVals = vColors;
    tr.ColorMap.Min.dVal = z1;
    tr.ColorMap.Max.dVal = z2;
    if(dp.SetColormap(tr))
    {
        GraphObject grBand = gl.GraphObjects("Spectrum1");
        if(grBand)
            grBand.Invalidate();
    }
}

EX2

// this example plots a XYZ contour and set its colormap by calling a utility function in page_utils.c
    void DataObject_SetColormap_ex2()
{
    int npts = 30;
    Worksheet wks;
    wks.Create();        
    wks.SetSize(-1,3);
    // fill wks with some XYZ data
    Dataset dsX(wks, 0);
    Dataset dsY(wks, 1);
    Dataset dsZ(wks, 2);
    dsX.Data(1, npts);
    dsX *= 0.05;
    dsY.Normal(npts);
    dsY += 1.2;
    dsZ.Normal(npts);
    // then we construct the XYZ data range
    DataRange dr;
    dr.Add(wks, 0, "X");
    dr.Add(wks, 1, "Y");
    dr.Add(wks, 2, "Z");
    // in this example, we will create a new graph, but you can use any exisitng graph layer
    // as long as the layer is a 2D layer
    GraphPage gp;
    // You must use a 3D scatter/line template, you can first make a 3d scatter plot, 
    // make needed modifications, then save your own
    gp.Create("TriContour");
    if( gp )
    {
        GraphLayer gl = gp.Layers();
        if( gl )
        {
            int nPlot = gl.AddPlot(dr, IDM_PLOT_TRI_CONTOUR);
            DataPlot dp = gl.DataPlots(nPlot);
            gl.Rescale();
            // now we will set the colormap, we have to assume here that the color spectrum gr object is already in the 
            // layer to show the colormap
            vector vLevels;
            vector<uint> vColors;
            vLevels.Data(0, 100, 5);
            int nLevels = vLevels.GetSize();
            double z1 = -1.5, z2 = 1.5;
            vLevels = z1 + (z2-z1)*vLevels/100.;
            vColors.SetSize(nLevels-1);
            for(int ii = 0; ii < vColors.GetSize(); ii++)
            {
                int gg = 255* ii / (nLevels-1);
                int bb = 255 * (nLevels-ii-1)/(nLevels-1);
                int nRGB = RGB(0, gg, bb);
                vColors[ii] = RGB2OCOLOR(nRGB);
            }
            
            dataplot_set_colormap(dp, vLevels, vColors, SYSCOLOR_RED, SYSCOLOR_PINK);
        }
    }
}


EX3

void    DataPlot_SetColormap_ex3()
{
    
    Worksheet wks;
    wks.Create("origin");
    Column colZ(wks, wks.AddCol());
    colZ.SetType(OKDATAOBJ_DESIGNATION_Z);
    
    Dataset ds1(wks,0);
    Dataset ds2(wks,1);
    Dataset ds3(wks,2);
    ds1.Data(1,20,1);
    ds2.Normal(20);
    ds3.Normal(20);
    
    GraphPage gp;
    gp.Create("TRICONTOUR");
    GraphLayer gl(gp.GetName(), 0);
    if(!gl)  
        return;
    gl.AddPlot(wks, IDM_PLOT_TRI_CONTOUR);
    
       DataPlot dp = gl.DataPlots(0); 
       if( !dp )
           return;
       
       vector     vZs = {-5, -2.5, 0, 2.5, 5};
    BOOL bRet = dp.SetColormap(vZs, false);
}

Remark

See Also

DataPlot::GetColormap

Header to Include

origin.h