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# William

Last seen: Today Active since 2012

Semi-retired physicist with interests in numerical modeling and mathematics.

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Bitshift cannot work on negative numbers
I believe this is happening for the following reason: The documentation states that "If A is a double array, and ASSUMEDTYPE is...

1 year ago | 2

How to calculate the conditional probability of an event?
Actually, I believe that p(C|A) would be: y = strfind(array, 'A'); N_A = length(y); p_CA = N_AC/N_A; There is one further th...

1 year ago | 1

How to calculate the conditional probability of an event?
Myriam, If A, B and C were variables with the values 1, 2 and 3, then in your example: array = [1, 1, 2, 1, 3, 1, 2, 2, 2, 3, ...

1 year ago | 0

How to calculate the conditional probability of an event?
Hello Myriam. It is not clear whether A, B, and C here are text characters, or if they have numeric values. If we assume they...

1 year ago | 0

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trigonometric non linear equation
I have no idea what this question is about, but I do notice that some of the expressions are surrounded with curly braces { } ra...

1 year ago | 1

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How to 3D plot a circle with radius of 1 in x y and sine wave in z?
How about this: theta = linspace(0,2*pi,100); x = sin(theta); y = cos(theta); z = sin(2*theta); figure(); plot3(x,y,z);

1 year ago | 3

Plotting a row in a Matrix
That would be: plot(sortpopulation(1:10,5));

1 year ago | 0

Adding each values to row vector
... but if you just want to create a vector with three values, you would use a statement like: a = [1,2,3]; This produces a ve...

1 year ago | 0

How do I plot a function over a specific range of x values?
Erica, I think fplot() will work if it is called correctly. If you want to use it, you need to define the function so that it ...

1 year ago | 0

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For loop execution.
I think it may be the 4 clauses that read like (t >= 0.1 & t <= 2.5). Shouldn't these say (t(d) >= 0.1 & t(d) <= 2.5)?

1 year ago | 0

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what function to use to find frequency of values in set?
... or maybe histcounts(R12) to get a histogram.

1 year ago | 0

Why do i get the error "Dimensions of arrays being concatenated are not consistent"
The problem in the second program is the statement 'theta(i) = theta', which is changing theta from a scalar into a vector. The...

1 year ago | 1

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Animate creation of a circle clockwise and anticlokwise for different staringpoints
Tim, A correction to the last message. If you want to go counterclockwise, you need to make the final angle bigger than the st...

1 year ago | 0

Animate creation of a circle clockwise and anticlokwise for different staringpoints
Hi Tim, Actually I have been thinking a little more about this, and I believe it is even easier than I suggested. You don't ne...

1 year ago | 0

Animate creation of a circle clockwise and anticlokwise for different staringpoints
Hi Tim, I don't think there is any problem with the cases you describe. The values of sin() and cos() are periodic in their ar...

1 year ago | 0

Animate creation of a circle clockwise and anticlokwise for different staringpoints
Tim, I think you could avoid all the special cases by making use of the atan2() function. This function is defined for points ...

1 year ago | 0

How to use for loop structure to calculate two vectors to dot product
a = 1:5; b = 6:10; c = 0; for j = 1:5 c = c + a(j)*b(j); end However, this calculation can be done more simply with t...

2 years ago | 0

Subtraction of elements in successive rows
The easy way to do this is A = diff(a);

2 years ago | 0

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How can i use fill3 to make a box
That's odd. I cut and pasted the code from your question and ran it. It produced a blue rectangle in the z=0 plane, which I th...

2 years ago | 0

Data saving for a loop
Nertila -- Yes, that is what this code does. Maybe it would be more clear if I wrote it in this way, with the k-index being the ...

2 years ago | 0

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Data saving for a loop
a = zeros(n,n,n) for i=1:n %calculus for j=1:n %calculus for k=1:n %calculus ...

2 years ago | 0

Why do I get this error?
One of the first two terms on the right should have an i+1 rather than i-1, but this is undoubtedly not the problem that caused ...

2 years ago | 0

Creating a loop to determine at which iteration an error has occurred
You don't necessarily need a loop for this. You can use B = diff(A) to return the differences between each pair of successive v...

2 years ago | 0

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How rotate a cylinder?
Lorenzo -- If all you need is to have the center of the cylinder located at the origin of the coordinate system, then what you n...

2 years ago | 0

How to use bar() to plot
I suspect the arguments to your plot() functions are reversed, When you type plot(a,b), Matlab puts 'a' on the x-axis ahd 'b' o...

2 years ago | 0

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Matlab question, very stuck
Your program seems to be a little uncertain about whether v is a number or a vector, and it also doesn't assign the values corre...

2 years ago | 0

Plotting square wave in matlab
Yes, the function square(x) returns a unique value, either +1 or -1, for each vallue of x. There is no value of x for which it ...

2 years ago | 1

How to do integral for data
I have two comments: A more correct statement about the integral is that the integral of sin(x) is equal to C-cos(x), where C i...

2 years ago | 0