使用绘图向量的MATLAB误差必须是相同的长度。

x = 0:1:5; % define x array 
y = exp(x)+x.^4+2*x.^2-x+3; % define y array
dx = diff(x); % 1 1 1 1 1 dx has one number less than x 
dy = diff(y); % -5 -1 -3 -4 -2
slope = dy./dx
z=exp(x)+4*x.^3 +4*x-1
plot(x,slope,'*',x,z)

'Error using plot Vectors must be the same length.'

“使用图向量的错误必须是相同的长度。”

Been stuck on this for a while, I am not sure what to do. ive seen the other responses to the same error but can not understand the code. It seems its the colon : that might help but i am not sure how to use it.

我被困在这里一段时间了，我不知道该怎么办。我看到了对相同错误的其他响应，但无法理解代码。它似乎是冒号:可能会有帮助，但我不知道如何使用它。

Any help would be appreciated!

如有任何帮助，我们将不胜感激!

1 个解决方案

#1

Since slope is computed from two consecutive values, I suggest you take the average betwen consecutive points as the x-axis values for ´slope`:

从两个连续值斜率计算之后,我建议你以平均前后连续点为轴´斜率值”:

plot((x(1:end-1)+x(2:end))/2,slope, '*',x,z)