Olivier,
I tried what you suggest. I understand what you are trying to do.
You added a small value (e.g.) your function to avoid getting zero.
But this doesn't resolve the fact that bin with zero content is not
assigned the correct color. I guess I can add small value uniformly to
my image to avoid zero content, but I believe bin with zero content
should be assigned the correct color.
Seng
On Mar 3, 2004, at 1:48 AM, Olivier Couet wrote:
>
>
> Hi Seng,
>
> try this:
>
> {
> TF2 *f2 = new
> TF2("f2","0.1+1000*((1-(x-2)*(x-2))*(1-(y-2)*(y-2)))",1,3,1,3)>
> Int_t ncol = 100;
> Int_t colors[ncol];
> TColor *col;
> Double_t dg=1/(Double_t)ncol;
> Double_t grey=0;
> for (Int_t i=0; i<ncol; i++) {
> colors[i]= i+100;
> col = gROOT->GetColor(colors[i]);
> col->SetRGB(grey, grey, grey);
> grey = grey+dg;
> }
> f2->SetContour(ncol);
> gStyle->SetPalette(100,colors);
> f2->Draw("colz");
> }
>
> Olivier
>
> On Tue, 2 Mar 2004, Woon-Seng Choong wrote:
>
>> I made a typo in my previous email. Here is the correct version.
>> Olivier just helped me to define more grayscale color. But when I draw
>> an image using 2D-histogram using the "col" or colz" option, bin with
>> zero content shows up as white (black being low count and white being
>> high count). It looks correct with "surf/color" draw option. In
>> addition, even in the DeepSea palette, bin with zero content still
>> shows up as white. My guess is no color is assigned to bin with zero
>> content. Is this a bug?
>>
>> Seng
>>
>>
>
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