I need help finding the volume underneath this surf plot. Or contour plot. We have a project including a sandbox with different heights of sand at different points. So create the plot I have used x = [50:50:950]; y = [50:50:950]; z = 'values from an xls spreadsheet. Containing every height value with 50mm spacing from 50 mm to 950 mm in both x and y directions'. [c,h] = contourm(x,y,z) ht=clabel(c,h); That's all I've done so far, I need to find the volume of sand in our sand box, and I know the width and length of it and also the height at those different locations. Please help, I'm completely lost!