simple problem about plotting

hello guys;
I am trying to plot a mathematics graph..
The graph is
y=(x+895.185)*(42.036*sqrt(x+657.509)-1656.4)-42.036*sqrt(x+657.509)*(x+1790.37)+2234.91*x+2.484*10.^6;
I made a code for this like below.
x=(0:0.1:1000);
y=(x+895.185)*(42.036*sqrt(x+657.509)-1656.4)-42.036*sqrt(x+657.509)*(x+1790.37)+2234.91*x+2.484*10.^6;
but I got the error massage...
how can I solve it?
thank you!

 采纳的回答

When you multiply a vector by another vector element by element, you need to use .* instead of * otherwise it tries to do a matrix multiplication. Fixed code:
y=(x+895.185).*(42.036*sqrt(x+657.509)-1656.4)-42.036*sqrt(x+657.509).*(x+1790.37)+2234.91*x+2.484*10.^6;

3 个评论

thank you!!
So when I use (), is it considered as vector in matlab?
No. When you did
x=(0:0.1:1000);
you made a vector. The parentheses were optional and unneeded. You could just have well have done
x = 0 : 0.1 : 1000;
and that would have been a vector too. And of course "sqrt(x+657.509)" is also a vector, and "(x+895.185)" is also a vector, and so is "(x+1790.37)" and "2234.91*x". You do not need a dot if you're multiplying a scalar (single number) times a vector, just when you want to multiply two vectors element by element, and of course they need to be the same length.
I got it!!
thank you for your kind answering!!

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