How to change the desired xaxis ticks and subsequent values in log log plot?

21 次查看（过去 30 天）
Raj Arora
Raj Arora 2024-1-24
回答： Constantino Carlos Reyes-Aldasoro 2024-1-24
I have a flood frequency analysis data stored in a file named "Matlabdataforgraph.txt." My intention is to visualize this data using MATLAB. To achieve this, I have specified a set of desired tick marks for the x-axis, arranged in reverse order. Successfully incorporating these ticks into my MATLAB plot, I now seek to create a logarithmic scale for the y-axis. However, I am encountering an issue where the x-axis values from the text file are not aligning with the desired tick marks in the plot, resulting in a deviation from the anticipated straight line in the plot. I have provided the data, MATLAB code, and an image illustrating the expected curve for your reference. Thanks in advance
MATLAB CODE
Q = importdata('Matlabdataforgraph.txt');
T1= rmmissing(Q(:,3));
T2= rmmissing(Q(:,4));
T3= rmmissing(Q(:,5));
T4= rmmissing(Q(:,8));
figure;
semilogy(T1,T4,'or','linewidth', 1.5)
hold on
semilogy(T1,T2,'--k','linewidth', 1.5)
semilogy(T1,T3,'--b','linewidth', 1.5)
semilogy(Q(:,1), Q(:,2),'o','MarkerEdge',[0 0 0],'MarkerSize',8,'MarkerFaceColor',[.7 .7 .7]);
desiredTicks = [1 5 20 40 60 80 90 95 98 99.5]; % Set the desired tick positions
numTicks = numel(desiredTicks);
logTicks = logspace(log10(desiredTicks(1)), log10(desiredTicks(end)), numTicks);
set(gca, 'XTick', logTicks);
set(gca, 'XTickLabel', arrayfun(@num2str, desiredTicks, 'UniformOutput', false));
xlim([1, 100])
mappedDataX = interp1(logspace(log10(desiredTicks(1)), log10(desiredTicks(end)), numel(desiredTicks)), desiredTicks, T1);
% Interpolate values in T1 to find their equivalent positions in the original scale
interpValues_original_scale = interp1(desiredTicks, logTicks, T1, 'linear', 'extrap');
hold on
a1 = Q(:, 3);
a1 = a1(~isnan(a1));
b1 = Q(:, 4);
b1 = b1(~isnan(b1));
c1 = Q(:, 5);
c1 = c1(~isnan(c1));
legend({'50% confidence level','95% confidence level',' 5% confidence level','Gaged peak Q (Bulletin 17B)','PILF (LO)'},'Location','Northwest','fontsize',12)
legend boxoff
ylim([1,1000000]);
ax = gca;
ax.XScale = 'log';
ax.XDir = 'reverse';
xlabel('Annual Exceedance Probability (%)','fontweight','bold','fontsize',18);
ylabel('Annual Maximum Discharge (cumecs)','fontweight','bold','fontsize',18);
set(gca,'linewidth', 1.5,'fontsize',12,'fontname','Times New Roman')
grid on
gridColor = [0.7, 0.7, 0.7]; % Light gray color
set(gca, 'GridColor', gridColor);
set(gca, 'MinorGridColor', gridColor);
set(gca, 'GridLineStyle', '-');
set(gca, 'MinorGridLineStyle', '-');
gridLineWidth = 0.7;
set(gca, 'LineWidth', gridLineWidth);
saveas(gcf, 'sample_figure.png');

请先登录，再回答此问题。

回答（1 个）

Constantino Carlos Reyes-Aldasoro
Ran in:
Hello
There are 2 separate properties that you have to handle, one is the ticks and the other is the ticklabels, and both are better managed if you use the handles effectively, for example
y=[ 0 1 2 9 6 5 9]; x = [1 2 3 4 5 6 7];
hAxis = gca;
hPlot = plot(x,y,'o');
If you do this in Matlab local, it will display a figure, here it will be displayed below.
Notice that I saved the handles of the axis and of the plot. Now we can modify the ticks and the labels.
hAxis.XTick = [1 1.5 2 3 5 6 11];
hAxis.YTickLabel{3}='three';
hAxis.YTickLabel{5}='F I V E';
In the lines above, I changed the values of xtick so that the ticks are placed in a certain location, not necessarily the same as the values of the data, and changed the values of yticklabel to anything you want.
I think if you use the properties, you will be able to fix your problem accordingly.

类别

在 Help Center 和 File Exchange 中查找有关 Annotations 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by