Basic Vector Operations
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Hello, I am currently familiarizing myself with MATLAB for my research. I was asked to create a program that reads in two vectors from the user and then graph them. I am currently having difficulty correctly performing the the addition and multiplication of these vectors. I am new to this website and MATLAB as a whole. I was hoping someone could assist me in any way.
Thank you, first and foremost for your support. I have spent the last couple of days researching operation techniques and I have come up with the following code for each different function (all of function data may not be included)
for addition:
a = get(handles.textvector1,'String');
b = get(handles.textvector2,'String');
%if length is the same
if length(a) == length(b)
%add vectors
c = a + b;
%set text to result
set(handles.textvectorresult,'String',c);
%plot result
plot(c)
% or display error message
else
errordlg('Please enter vectors of same size','Size mismatch error','modal')
end
and for multiplication:
a = get(handles.textvector1,'String');
b = get(handles.textvector2,'String');
%if length is the same
if length(a) == length(b)
%add vectors
c = a .* b;
%set text to result
set(handles.textvectorresult,'String',c);
%plot result
plot(c)
% or display error message
else
errordlg('Please enter vectors of same size','Size mismatch error','modal')
end
I end up getting unusually high numbers
Thanks, Prince Njoku
1 个评论
Oleg Komarov
2011-5-23
http://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer
采纳的回答
Oleg Komarov
2011-5-23
- Multiplication (note the dimensions):
(1:10) * (21:30).' = scalar % 1 by 10 times 10 by 1 - inner/dot product
(1:10).' * (21:30) = matrix % 10 by 1 times 1 by 10 - outer product
(1:10) .* (21:30) = vector % elementwise multiplication
.
- Summation (again note the dimensions)
(1:10) + 10 or rand(2) + 10 % vector/matrix plus scalar
(1:10) + (11:20) % same dim vector addition
rand(2) + ones(2) % same dim matrix addition
EDIT
You're retrieving text and doing operations on strings not numbers. To see what I mean try this:
'65' .* '33'
65 * 33
To convert strings to numbers a wrapper is:
str2double('65')
or manually for positive numbers:
tmp = '65' - '0';
nTmp = numel(tmp);
out = tmp*(10.^(nTmp-1:-1:0)).';
7 个评论
Prince
2011-5-23
Oleg Komarov
2011-5-23
Can you please post an example input string and what you're trying to accomplish.
Does tmp = '65' - '0'; satisfy your request (to separate a string in numeric integers)?
Prince
2011-5-23
Prince
2011-5-23
Oleg Komarov
2011-5-23
vector1 + vector2 gives exactly result if they are numeric.
If they are strings
vec1 = '12345';
vec2 = '24562';
Then you need to convert into separate integers.
vec1 -'0' does exactly that.
A string number (ex: '1') is decoded with it's corresponding ASCII numeric value, thus '1' -->double('1') = 49.
'1'-'0' = 49 - 48 = 1 and the result is displayed as double because of the operator "minus".
'123' - '0' operates on all elements of the string array and returns a double vector [1 2 3] and not the scalar 123 directly.
Prince
2011-5-23
westley
2025-7-30
thank you so much man!
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