How do I plot x,y, and an intensity value on an xy-plane with the intensity on a color scale?

I have this code right now:

% Make an image of the points, then apply a colormap
x = x(:); % Extract x value
y = y(:); % Extract y value
v=v(:);
%find max and min values
minX = min(x,[],1);
maxX = max(x,[],1);
minY = min(y,[],1);
maxY = max(y,[],1);
%dealing with NaN
v(isnan(v)) = 0; %set all NaN to zero
minV=0;
maxV=max(v,[],1);
% Make image be 500 by 700
rows = 500;
columns = 700;
grayImage = zeros(rows, columns, 'uint8');
for k = 1 : length(x)
    row = ceil((y(k) - minY) * rows / (maxY - minY));
    column = ceil((x(k) - minX) * columns / (maxX - minX));
  if (row == 0)
    row = 1;
  end
  if (column == 0)
    column = 1;
  end
  grayImage(row, column) = uint8(255 * (v(k) - minV) / (maxV - minV));
end
imshow(grayImage);
colorbar;
% Colormap is not gray scale.
% Apply some other colormap if you want
colormap(jet(256))

Answer 1

[Walter Roberson]

cmap = jet(256);
imshow(grayImage, cmap);
colorbar();