How to add text on the figure without unknown x and y coordinates ?

Question

Onur Hakverdi 2021-6-23

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/863275-how-to-add-text-on-the-figure-without-unknown-x-and-y-coordinates

评论： Image Analyst 2021-6-23

Hi i have a csv file the problem is my data has random x,y values so it changes according to machine but i want to display a value on the figure. I tried something like this v = (intensity/intensity_max)*100; text(x,y,(v) but it didn't work because of the x and y values. How can i overcome on this problem ?

2 个评论
显示无隐藏无

Steven Lord 2021-6-23

See this previous discussion for more context.

Onur Hakverdi 2021-6-23

hi it doesn't include a solution for my issue.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Image Analyst 2021-6-23

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/863275-how-to-add-text-on-the-figure-without-unknown-x-and-y-coordinates#answer_731805

在 MATLAB Online 中打开

spectroscopy.csv

The problem was you were printing an entire array of thousands of elements instead of a single number.

This seems to work. Adapt as needed.

% Demo to print the peak on a spectrogram.
clc;    % Clear the command window.
fprintf('Beginning to run %s.m ...\n', mfilename);
close all;  % Close all figures (except those of imtool.)
clearvars;
workspace;  % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 18;
inputFolder = pwd;
fullFileName = fullfile(inputFolder, 'spectroscopy.csv')
data = csvread(fullFileName);
wavelength = data(:,2);
intensity = data(:,1);
[intensity_max, index] = max(intensity)
wavelength_max = wavelength(index);
plot(wavelength,intensity, 'b-');
hold on;
plot(wavelength_max, intensity_max, 'ro', 'MarkerSize', 11, 'LineWidth', 2);
xlabel('Wavelength', 'FontSize', fontSize);
ylabel('Intensity', 'FontSize', fontSize);
grid on;
% Compute normalized intensity vector, but strangely enough, we never use it.
normalizedIntensity = (intensity / intensity_max) * 100;
% Print max value next to the peak of the curve.
xText = wavelength_max
yText = intensity_max
textLabel = sprintf('  The Max Intensity is %.7f', intensity_max)
text(xText, yText, textLabel, 'horizontalalignment', 'left', 'Color', 'r', 'FontWeight', 'bold', 'FontSize', 14);
% Give a title.
if  333800 < intensity_max && intensity_max < 345100
	title('Cu-I', 'FontSize', fontSize)
elseif 862000 < intensity_max && intensity_max < 90550
	title('Al-I', 'FontSize', fontSize)
elseif 4200 < intensity_max && intensity_max < 5720
	title('C-I', 'FontSize', fontSize)
elseif 209 < intensity_max && intensity_max < 211
	title('C-II', 'FontSize', fontSize)
else
	title('Unknown species', 'FontSize', fontSize);
end
outputFolder = 'C:\Plots\';
if ~isfolder(outputFolder)
	% Create folder if it dows not exist.
	mkdir(outputFolder);
end
fullOutputFileName = fullfile(outputFolder, 'Plot.png')
% saveas(gcf, fullOutputFileName); % Old: pre R2020a
% exportgraphics(gca, fullOutputFileName);  % New: R2020a or newer
fprintf('Done!\n');

2 个评论
显示无隐藏无

Onur Hakverdi 2021-6-23

编辑：Image Analyst 2021-6-23

That is awesome job. I just only wanted a percentage value on the figure, but logic is true. Instead of "The Max Intensity is 209.45", I wanted "The percentage of is %90.xx" like this. I couldn't explain my problem very well, so probably people were thinking wrong.

Image Analyst 2021-6-23

@Onur Hakverdi, of course the peak is at 100%, and all the rest of the thousands of values are like 50% or so. And surely you don't want thousands of text labels on there - you wouldn't be able to see your data.

If you don't want what I put, then you can change sprintf() to have it say exactly what you want. Just don't put the whole array name into sprintf() or it will try to use each one of those thousands of array elements over and over again with the format string.

请先登录，再进行评论。

Answer 2

Scott MacKenzie 2021-6-23

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/863275-how-to-add-text-on-the-figure-without-unknown-x-and-y-coordinates#answer_731580

在 MATLAB Online 中打开

To print 'hello' in the center of the figure... (adjust accordingly)

ax = gca;
x = ax.XLim(1) + (ax.XLim(2) - ax.XLim(1)) / 2;
y = ax.YLim(1) + (ax.YLim(2) - ax.YLim(1)) / 2;
text(x, y, 'hello', 'horizontalalignment', 'center');