matlab - Finding the area of some specific graph color in a 3D graph -

i have graph (and raw data) shown below.

the axis in graph in cm. want know area of deep blue area in graph (the answer should 20 sq.cm. or that). there way find it?

if you're sure literally mean deepest shade of blue, corresponds minimum of data. can find minval = min(mydata(:));.

once have minimum value, select points equal value minvals = mydata == minval;. note collect elements equal deepest blue, in floating point sense. if didn't literally mean deepest shade of blue, might want consider selecting points within threshold of minimum value instead. count them total = sum(minvals(:));.

then multiply number of points value representing area of each point in cm2.