Define isotherm depth from XBT data

Hi I have matfile that contain 3 data:

Depth = [1 10 25 50 75 100 125 150 200 250]; %dim 1x10 in meter

Date =[732114 732144 732175]; %in datenum, dim 1x3;

Temp = [29.5 29.4 28.2 25.1 23.2 22.1 18.2 15.1 13.2;

       29.4 29.35 27.8 25.2 22.9 22.2 18.1 14.9 13.7;

       29.5 29.4 28.2 25.1 23.2 22.1 18.2 15.1 13.2]; %dim 3x10 in degree Celcius

Would you please help me how to find isotherm depth at 20degree Celcius?

I expect the result is D20 with matrix 1 x 3 (D20 each Date)

When I'm using

Tiso = 20 T20 = find(Temp)>Tiso it seem the matrix will dissolve all value in temp not per row.

Would you please help me

[m0xty Wilopo]

Done!