Matlab: x v/s y坐标。

I want to plot a function y=1-exp(c) ,where as the range of x is defined. The plot is to be between x and the function y. The plot just shows just 1 point instead of showing a series of points exponentially.I am new in Matlab.Sp,please help me where I am going wrong Here is the code:

我想画出一个函数y=1-exp(c)在x的取值范围内。这个图是在x和y之间，这个图只显示了1个点而不是指数级数。我是新手。Sp，请帮助我在哪里出错这是代码:

   for x = -10:0.25:10

   if(x>0)

   c=-6*x;
   m=exp(c);
   y = 1-m  

   end
   plot(x,y,'o')
   xlabel('x') 
   ylabel('y') 
   title('Plot')
   end

2 个解决方案

#1

This should do it:

这应该这样做:

x = -10:0.25:10; % define the x vector
c=  -5*x.*(x>0); % using a  logical condition the 'if' is avoided
y = 1-exp(c);    % calc y given c

plot(x,y,'o')
xlabel('x') 
ylabel('y') 
title('Plot')

no 'for' loop or 'if' needed...

没有“for”循环或“如果”需要……

#2

Your problem is the for loop. It is resetting the value of y and re-ploting that one point each loop. You don't need that loop at all. This code will do the trick for y = 1-exp(A*x)

你的问题是for循环。它重新设置y的值并重新绘制每个循环的一个点。你根本不需要那个循环。这段代码将对y = 1-exp(A*x)进行操作

Edit (2012-10-30) OP says y is zero for x<=0. @Nate's code in the answer above is probably best, but here I use logical indexing to show a different way to do the same thing.

编辑(2012-10-30)OP说，y =0, x<=0。在上面的答案中，@Nate的代码可能是最好的，但是在这里，我使用逻辑索引来显示一种不同的方法来做同样的事情。

x = -10:0.25:10; % <vector>
y = zeros(size(x)); % prealocate y with zeros and make it the same size as x
y(x>0) = 1 - exp(-5*x(x>0)); % only calculate y values for x>0
plot(x,y,'o')
xlabel('x')
ylabel('y')
title('Plot')

#1