How can I remove the white edge in the density map?

Question

Lightisthenight 2019-6-26

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/468997-how-can-i-remove-the-white-edge-in-the-density-map

评论： Adam Danz 2019-6-26

I used imagesc to plot a density map and plotted an additional point (the red one) in the figure to highlight that this is my basepoint. As seen in the image there is white edge at the x-axis of my density map, I probably think that there is no density points at that area. How can I turn this white edge to blue which is according to the colorbar 0 density.

I tried to extend the limit scale of 'ydata' before, this will result to a wrong density map, such that points below my basepoint are plotted.

testtri = worldpointscorrtri; % points i want to illustrate in density map
grid1 = 256;  %refinement of map
minvalstri = min(testtri);
maxvalstri = max(testtri);
rangevalstri = maxvalstri - minvalstri;
xidxtri = 1 + round((testtri(:,1) - minvalstri(1)) ./ rangevalstri(1) * (grid1-1));
yidxtri = 1 + round((testtri(:,2) - minvalstri(2)) ./ rangevalstri(2) * (grid1-1));
densitytri = accumarray([yidxtri, xidxtri], 1, [grid1,grid1]);  %note y is rows, x is col
densitytri = densitytri.*(1/max(densitytri,[], 'all')); 
imagesc(densitytri, 'xdata', [minvalstri(1), maxvalstri(1)], 'ydata', [minvalstri(2), maxvalstri(2)]);
hold on;
plot(worldpoints_meltcorrtri(:, 1), worldpoints_meltcorrtri(:, 2), 'r*');
colorbar;
axis  tight ;
axis square;
xlabel('x in mm ')
ylabel('-y in mm ')

2 个评论
显示无隐藏无

KALYAN ACHARJYA 2019-6-26

worldpointscorrtri??

Lightisthenight 2019-6-26

编辑：Lightisthenight 2019-6-26

this is just my image points, a 5000x3 matrix, I just corrected it in the question

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Adam Danz 2019-6-26

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/468997-how-can-i-remove-the-white-edge-in-the-density-map#answer_380917

编辑：Adam Danz 2019-6-26

在 MATLAB Online 中打开

Try this

axis tight
xlim([minvalstri(1), maxvalstri(1)])
ylim([minvalstri(2), maxvalstri(2)])

Note that these points are the centers of the corner squares so you'll cut off 1/2 of the upper, lower, right and left eges. Your resoltuion looks tiny so this won't be noticible but you might want to account for this issue by adding +/-1/2 of your square size to the axis limits.