Answered

Coding a quadratic root finder

One error: you want to check the sign of (b*b-4*a*c), not sqrt(b*b-4*a*c) The case of two complex roots works exactly like tw...

Coding a quadratic root finder

One error: you want to check the sign of (b*b-4*a*c), not sqrt(b*b-4*a*c) The case of two complex roots works exactly like tw...

7 hours ago | 0

Answered

How can I generate a colour map of points based on their distance from a plane?

I haven't tested, but I think something like this should work: % bin b1 & b2 into 10 & 30 bins, respectively [b1_bin,b1_edge] ...

How can I generate a colour map of points based on their distance from a plane?

I haven't tested, but I think something like this should work: % bin b1 & b2 into 10 & 30 bins, respectively [b1_bin,b1_edge] ...

13 hours ago | 0

Answered

Is there a way to put a marker on all of the points where y=0 on a plot?

Assuming you have access to the data (x,y) which generated the plot: % generate sample x,y x=1:1000; % generate 1000 random i...

Is there a way to put a marker on all of the points where y=0 on a plot?

Assuming you have access to the data (x,y) which generated the plot: % generate sample x,y x=1:1000; % generate 1000 random i...

15 hours ago | 0

Answered

indexing into a matrix

A([1 3 end-1],:) I highly recommend this explanation of indexing: https://www.mathworks.com/company/newsletters/articles/matrix...

indexing into a matrix

A([1 3 end-1],:) I highly recommend this explanation of indexing: https://www.mathworks.com/company/newsletters/articles/matrix...

16 hours ago | 0

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Answered

aggregate data of a dataset

check out splitapply. You may need to change the format of your data, but it does exactly what you want: G = findgroups(ds.seat...

aggregate data of a dataset

check out splitapply. You may need to change the format of your data, but it does exactly what you want: G = findgroups(ds.seat...

17 hours ago | 0

| accepted

Answered

Array indices must be positive integers or logical values.

You are trying to access Re(i),V(i),etc. with i=1.02. There doesn't seem to be anywhere that you use i as a number rather than i...

Array indices must be positive integers or logical values.

You are trying to access Re(i),V(i),etc. with i=1.02. There doesn't seem to be anywhere that you use i as a number rather than i...

17 hours ago | 1

Answered

How do I replace an image on a graph and replace it with a new image, whilst keeping all other images in their place?

ball_handle = fill(x,y,c); %or secondhand through drawshapeNew ... ball_handle.Vertices = ball_handle.Vertices + [xtranslate y...

How do I replace an image on a graph and replace it with a new image, whilst keeping all other images in their place?

ball_handle = fill(x,y,c); %or secondhand through drawshapeNew ... ball_handle.Vertices = ball_handle.Vertices + [xtranslate y...

18 hours ago | 1

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Answered

how to Obtain the algebraic and geometric multiplicity of each eigenvalue of any square matrix

eig(A) gives you the eigenvalues. You can count occurrences for algebraic multiplicity. Geometric seems more complicated, but I ...

how to Obtain the algebraic and geometric multiplicity of each eigenvalue of any square matrix

eig(A) gives you the eigenvalues. You can count occurrences for algebraic multiplicity. Geometric seems more complicated, but I ...

1 day ago | 2

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Answered

How do I replace an image on a graph and replace it with a new image, whilst keeping all other images in their place?

Depending on how you are drawing the ball, you may be able to update it's position rather than drawing a new one. If not, you co...

How do I replace an image on a graph and replace it with a new image, whilst keeping all other images in their place?

Depending on how you are drawing the ball, you may be able to update it's position rather than drawing a new one. If not, you co...

1 day ago | 1

Answered

using break and continue to using true extend ?

It sounds like you want to check the conditions with if statements inside your while loop: while true % do stuff Mass...

using break and continue to using true extend ?

It sounds like you want to check the conditions with if statements inside your while loop: while true % do stuff Mass...

1 day ago | 0

Answered

using non number vectors and number vectors in the same fprintf command (beginner)

There is no good reason to do this in a single fprintf command, and the workaround necessary to do it would be painful. Do this:...

using non number vectors and number vectors in the same fprintf command (beginner)

There is no good reason to do this in a single fprintf command, and the workaround necessary to do it would be painful. Do this:...

1 day ago | 0

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Answered

changing a group of numbers in a vector

Does this do it or do you need individual cycles to be different lengths? % total number of elements N = 3501; % number of "o...

changing a group of numbers in a vector

Does this do it or do you need individual cycles to be different lengths? % total number of elements N = 3501; % number of "o...

1 day ago | 0

Answered

Random Number Generator with range between numbers

instead of (weighted) averaging your old velocity and a new random velocity, just modify your old velocity by a smaller random n...

Random Number Generator with range between numbers

instead of (weighted) averaging your old velocity and a new random velocity, just modify your old velocity by a smaller random n...

3 days ago | 0

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Answered

Transform char variable to matrix

tmp={'002,005';'002,003';'002,005'}; NewVar=str2double(split(tmp,','))

Transform char variable to matrix

tmp={'002,005';'002,003';'002,005'}; NewVar=str2double(split(tmp,','))

3 days ago | 0

Answered

How to plot and save a figure with consolidated plots as well as splitted plots in loop?

Presumably you are calculating or loading each batch. To distinguish in this simple example, I add the index to the data x=[1:5...

How to plot and save a figure with consolidated plots as well as splitted plots in loop?

Presumably you are calculating or loading each batch. To distinguish in this simple example, I add the index to the data x=[1:5...

3 days ago | 0

Answered

Setting a value for multiple axes handles at once (without a for-loop)

Setting a value for multiple handles is pretty easy: set(axs,'Units','centimeters') getting values is a little trickier. For y...

Setting a value for multiple axes handles at once (without a for-loop)

Setting a value for multiple handles is pretty easy: set(axs,'Units','centimeters') getting values is a little trickier. For y...

3 days ago | 0

Answered

Array of index, should return indexed values on the same array format

It sounds like weights = v(m); should work

Array of index, should return indexed values on the same array format

It sounds like weights = v(m); should work

5 days ago | 0

Answered

How to find the mean of categorical data

check out splitapply. You may need to change the format of your data, but it does exactly what you want: G = findgroups(Day); ...

How to find the mean of categorical data

check out splitapply. You may need to change the format of your data, but it does exactly what you want: G = findgroups(Day); ...

5 days ago | 0

Answered

What is the inversion method used in (inv) function in MATLAB

read the documentation: "inv performs an LU decomposition of the input matrix (or an LDL decomposition if the input matrix is H...

What is the inversion method used in (inv) function in MATLAB

read the documentation: "inv performs an LU decomposition of the input matrix (or an LDL decomposition if the input matrix is H...

5 days ago | 1

| accepted

Answered

How would one tablize the iterations from a while loop with the variables at the top?

something like this will work, but may not be the most efficient depending on the number of iterations: tol = 1e-5; c_old = In...

How would one tablize the iterations from a while loop with the variables at the top?

something like this will work, but may not be the most efficient depending on the number of iterations: tol = 1e-5; c_old = In...

5 days ago | 0

Answered

Error: Array indices must be positive integers or logical values. Why??

you need a '*' between 'z' and the parenthesis. It is interpreting z(...) as indexing z

Error: Array indices must be positive integers or logical values. Why??

you need a '*' between 'z' and the parenthesis. It is interpreting z(...) as indexing z

5 days ago | 0

Answered

how to find max value of a function with a for loop

Loop isn't necessary unless you can't store the data in memory: e=y-(m*x-b); [e_max,idx] = max(e); x_max = x(idx); y_max = y...

how to find max value of a function with a for loop

Loop isn't necessary unless you can't store the data in memory: e=y-(m*x-b); [e_max,idx] = max(e); x_max = x(idx); y_max = y...

7 days ago | 0

Answered

Storing all for-loop results of a specific variable in .mat-file

Assuming all the produced data can fit in memory: for ta=1:20 a = 3; % save each value in an array va(ta) = (ta.*a)...

Storing all for-loop results of a specific variable in .mat-file

Assuming all the produced data can fit in memory: for ta=1:20 a = 3; % save each value in an array va(ta) = (ta.*a)...

7 days ago | 0

Answered

Select Specific Values in Matrix Based on Index Values Listed in Array...

Actually, you can index directly with 'b' after loading your variable into 'a': a(b,:) It may be possible to only load the row...

Select Specific Values in Matrix Based on Index Values Listed in Array...

Actually, you can index directly with 'b' after loading your variable into 'a': a(b,:) It may be possible to only load the row...

7 days ago | 0

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Answered

How to add both title and change the scale of a color bar

cb=colorbar(); cb.Label.String = 'Electric Potential Field, V'; cb.Ticks = -45:15:150; caxis([-45 150]);

How to add both title and change the scale of a color bar

cb=colorbar(); cb.Label.String = 'Electric Potential Field, V'; cb.Ticks = -45:15:150; caxis([-45 150]);

12 days ago | 0

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Answered

Using the result as a input in the loop again

Change Mw1(x)=(mW+M(x)/18.0); to % first iteration assumes Mw1(0) = 0 if x==1 Mw1(x)=mW; % later loops access the valu...

Using the result as a input in the loop again

Change Mw1(x)=(mW+M(x)/18.0); to % first iteration assumes Mw1(0) = 0 if x==1 Mw1(x)=mW; % later loops access the valu...

19 days ago | 0

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Answered

How to sort a matrix by a predefined order

A=[1 2; 7 8; 5 6; 3 4]; B=[1; 4; 3; 2]; A = A(B,:);

How to sort a matrix by a predefined order

A=[1 2; 7 8; 5 6; 3 4]; B=[1; 4; 3; 2]; A = A(B,:);

19 days ago | 0

| accepted

Answered

Question on using interpolate function

Check your data again. "data" is slightly less than 5 until x=0.485, and the first point exactly equal to 5 is x=1.71. You could...

Question on using interpolate function

Check your data again. "data" is slightly less than 5 until x=0.485, and the first point exactly equal to 5 is x=1.71. You could...

19 days ago | 1

| accepted