Matlab绘图添加直角坐标轴

绘制y=x^2，并添加直角坐标轴。

clear;clc;close all

%% 绘制方程

x = -10:0.01:10;

figure;

y = x.^2-30;

plot(x,y,'k','linewidth',2)

axis off

set(gcf,'Position',[100 100 360 420]);

w1 = min(y);

w2 = max(y);

%% 绘制坐标轴

xlim = max(abs(x));

ylim = max(abs([w1 w2]));

axis(gca,[-xlim xlim -ylim ylim]);

xx = get(gca,'xtick');

yy = get(gca,'ytick');

dx = mean(diff(yy))/5;

dy = mean(diff(xx))/5;

axis(gca,[-xlim xlim -ylim ylim]);

set(gca,'units','normalized');

pos1 = get(gca,'position');

s1 = [pos1(1) pos1(2)+pos1(4)/2];

s2 = [pos1(1)+pos1(3) pos1(2)+pos1(4)/2];

s3 = [pos1(1)+pos1(3)/2 pos1(2)];

s4 = [pos1(1)+pos1(3)/2 pos1(2)+pos1(4)];

annotation('arrow',[s1(1) s2(1)],[s1(2) s2(2)])

annotation('arrow',[s3(1) s4(1)],[s3(2) s4(2)])

% 显示坐标轴标注

text(max(x)-2,-2,'x') % 自己动手调整

text(1,max(y)-2,'y') % 自己动手调整

text(-1,-2,'0') % 自己动手调整

%% 保存图片

saveas(gcf,'pic.png')