MATLAB中不显示刻度修改X轴范围及数据点可见性问题

Hey there! Let's work through your two MATLAB questions step by step:

The trick here is to split the task into two parts: first set your desired X-axis range, then explicitly define which ticks you want to show (hiding any new ticks that come with the expanded range). Here are two common scenarios:

Scenario 1: Expand X-axis range but keep only original data ticks #

Suppose your data spans x=1:8, but you want the X-axis to show from 0 to 9 without displaying ticks for 0 or 9. Use this code:

% After your plotting code
xlim([0 9]); % Set your custom X-axis range
xticks(1:8); % Only show ticks for your original data points

Scenario 2: Hide all X-axis ticks entirely #

If you want to adjust the X-axis range and show no ticks at all (labels and tick marks), use:

xlim([your_min your_max]);
xticks([]); % This removes all tick marks and labels

You can also add xticklabels([]) for extra safety, though xticks([]) usually handles both.

Looking at your data, the 5th and 6th points have the same y value (80), so their markers overlap completely. Here are three straightforward fixes:

Fix 1: Slightly offset the X positions of overlapping points #

This moves the points just enough to separate them visually, while keeping the X-axis ticks aligned with your original feature counts:

x = 1:8;
x(5) = 4.8; % Shift 5th point left slightly
x(6) = 5.2; % Shift 6th point right slightly
y = [70 74 77 78 80 80 82 83];
err = [14 11 12 10 10 7 7 5];

% Add markers and increase their size for better visibility
errorbar(x,y,err,'red','marker','o','markersize',8); 
ylabel('Classification results','fontsize',20);
xlabel('Nr of features used', 'fontsize',20);
title('Feature selection with Genetic Algorithm','fontsize',24);
ylim([55 100]);
xticks(1:8); % Keep original X ticks even with shifted points

Fix 2: Use different markers for overlapping points #

If you don't want to shift X positions, use distinct marker shapes to tell the points apart:

x = 1:8;
y = [70 74 77 78 80 80 82 83];
err = [14 11 12 10 10 7 7 5];

% Plot all points first with a base marker
errorbar(x,y,err,'red','marker','o','markersize',6);
hold on;
% Overplot the two overlapping points with unique markers
errorbar(x(5),y(5),err(5),'red','marker','s','markersize',8); % Square marker
errorbar(x(6),y(6),err(6),'red','marker','^','markersize',8); % Triangle marker
hold off;

ylabel('Classification results','fontsize',20);
xlabel('Nr of features used', 'fontsize',20);
title('Feature selection with Genetic Algorithm','fontsize',24);
ylim([55 100]);

Fix 3: Increase marker size and add distinct colors #

Make the markers larger and use different face/edge colors to make overlapping points stand out:

errorbar(x,y,err,'red','marker','o','markersize',10,'markerfacecolor','white','markeredgewidth',2);
% For the overlapping points, change the face color
hold on;
errorbar(x(5),y(5),err(5),'red','marker','o','markersize',10,'markerfacecolor','blue','markeredgewidth',2);
hold off;

All these methods will make the two overlapping points easy to distinguish without altering your core data.

内容的提问来源于stack exchange，提问作者Pugl