Plotting scatter plot using X coordinate matrix and Y coordinate matrix

Hello,

I have 2 matrices (18x76): one for x coordinate location and one for y coordinate location representing nodes.

I want to plot these nodes in a scatterplot using a for loop. I also want to have an if statement saying "if the x coordinate is greater than 15, don't plot a pixel there" and "if the y coordinate is greater than 3, don't plot a pixel there".

For example, matrix X(4,5) = 0.9 and matrixY(4,5) = 0.5196 so there should be a red circle on the graph at that location.

Here is the working code I have so far: Please let me know if this doesn't make sense. Any help would be appreciated!

for x_coor_col=1:76
    for x_coor_row=1:18
        for y_coor_col=1:76
            for y_coor_row=1:18
                if x_coor(x_coor_row,x_coor_col) > 15 | y_coor(y_coor_row,y_coor_col) > 3
                    %don't plot pixel
                else
                    % plot a pixel at that location
                end
            end
        end
    end
end

[Jan]

"there should be a red circle on the graph at that location" - at which location? [4,5] or [0.9, 0.5196]?

[Radhika Kulkarni]

at ( 0.9, 0.5196)

[KALYAN ACHARJYA]

Is this ? DO Modify as per requiremnets. Still, I'm not clear about the question, so I've posted comments

x_coor=randi(20,[18,76]);
y_coor=randi(20,[18,76]);
mask=x_coor> 15 | y_coor > 3;
%Plot Data with red color
scatter(x_coor(mask),y_coor(mask),'ro','linewidth',2);
hold on;
% Donot Plot data with blue color
scatter(x_coor(~mask),y_coor(~mask),'b*','linewidth',2);

If you dont want 2nd one, just delete the last line.

Answer 1

[dpb]

Don't need any loops

X=x_coor(:); Y=y_coor(:);       % vector; not required to plot, just to keep original data unchanged
XLIM=15; YLIM=3;                % the limits, use variables so can change easily
X(X>XLIM)=nan; Y(Y>YLIM)=nan;   % plotting routines ignore NaNs
hSc=scatter(X,Y,2,'filled')

Fiddle with size, color and whether want filled or not to suit tastes...