Interested in external applications, mex & engine applications with Fortran, C, C++, etc, particularly in the areas of speed improvement and memory management efficiencies.

Answered

error when running a function

Do not push the green triangle "go" button in the editor since that calls the function without any input arguments. Instead, cal...

error when running a function

Do not push the green triangle "go" button in the editor since that calls the function without any input arguments. Instead, cal...

ongeveer 11 uur ago | 0

Answered

solving a set of differential equations with ode45

Initial conditions is a 4-element vector: IC1=[0; 0; 298; 298]; But in your derivative function you have this: M=[5,15,25,55]...

solving a set of differential equations with ode45

Initial conditions is a 4-element vector: IC1=[0; 0; 298; 298]; But in your derivative function you have this: M=[5,15,25,55]...

ongeveer 16 uur ago | 0

| accepted

Answered

Loops - physics - nonlinear gravity & acceleration

Your immediate problem is that h is a vector, so the right hand side of this statement is a vector: g(i+1)=(400000000/(6371+h...

Loops - physics - nonlinear gravity & acceleration

Your immediate problem is that h is a vector, so the right hand side of this statement is a vector: g(i+1)=(400000000/(6371+h...

ongeveer 16 uur ago | 0

Answered

Looping over column and returning values where conditions are met

In general, perform find( ) on the condition you want. E.g., find(matrix(:,4)>80) would return the row numbers where the 4th c...

Looping over column and returning values where conditions are met

In general, perform find( ) on the condition you want. E.g., find(matrix(:,4)>80) would return the row numbers where the 4th c...

1 dag ago | 0

Answered

sparse half-precision matrices

The sparse format in MATLAB only supports double and logical data types. To use any other data type you would have to write all...

sparse half-precision matrices

The sparse format in MATLAB only supports double and logical data types. To use any other data type you would have to write all...

1 dag ago | 0

| accepted

Answered

RK4/AB4, need help with correct code for 2 second order equations in Matlab

So, first define a 4-element state vector. To keep the nomenclature the same as the MATLAB docs, I will use the variable name y....

RK4/AB4, need help with correct code for 2 second order equations in Matlab

So, first define a 4-element state vector. To keep the nomenclature the same as the MATLAB docs, I will use the variable name y....

1 dag ago | 0

Answered

Cell Arrays and Indexing?

This is the reverse of your last assignment. It needs only one loop over the number of rows, and the cell array element for tha...

Cell Arrays and Indexing?

This is the reverse of your last assignment. It needs only one loop over the number of rows, and the cell array element for tha...

2 dagen ago | 0

| accepted

Answered

Cell arrays and Indexing with Cells HELP?

This row = Q(1:end); col = Q{1:end}; Z(row, col) = true; is actually a good attempt and shows you understand the problem .....

Cell arrays and Indexing with Cells HELP?

This row = Q(1:end); col = Q{1:end}; Z(row, col) = true; is actually a good attempt and shows you understand the problem .....

2 dagen ago | 0

| accepted

Answered

repeat the iteration with an error using try/catch

Maybe this construct does what you want while( true ) try MyProgramHere ...

repeat the iteration with an error using try/catch

Maybe this construct does what you want while( true ) try MyProgramHere ...

2 dagen ago | 0

Answered

Storing doubles in the smallest integer class for which they fit without changing their value?

Some hints: Don't use loops, use vectorized code to figure out which integer size works. intmax(type) gives you the largest va...

Storing doubles in the smallest integer class for which they fit without changing their value?

Some hints: Don't use loops, use vectorized code to figure out which integer size works. intmax(type) gives you the largest va...

3 dagen ago | 0

| accepted

Answered

How do I make a function work with vectors?

Use element-wise divide operator ./ (with the dot) instead of the matrix divide operator / (without the dot). E.g., tanH(x)=((...

How do I make a function work with vectors?

Use element-wise divide operator ./ (with the dot) instead of the matrix divide operator / (without the dot). E.g., tanH(x)=((...

3 dagen ago | 0

| accepted

Answered

Question already answered - ODE solving use RK4

Your basic problem is that you have two states, x and y, but your function arguments are inconsistent with this. Take this code:...

Question already answered - ODE solving use RK4

Your basic problem is that you have two states, x and y, but your function arguments are inconsistent with this. Take this code:...

3 dagen ago | 1

| accepted

Answered

Really! fprintf cell error

What happens if you change this fprintf(fid, '%d %s %s %f',shape{i,:}); to this fprintf(fid, '%d %s %s %f',shape{i,1},shape{i...

Really! fprintf cell error

What happens if you change this fprintf(fid, '%d %s %s %f',shape{i,:}); to this fprintf(fid, '%d %s %s %f',shape{i,1},shape{i...

3 dagen ago | 0

| accepted

Answered

MATLAB Homework Problem: "Incorrect use of '=' operator" in a for loop

This: for (i = 2:0.5:15 && j = -2:0.5:12) Needs to be two nested loops: for i = 2:0.5:15 for j = -2:0.5:12

MATLAB Homework Problem: "Incorrect use of '=' operator" in a for loop

This: for (i = 2:0.5:15 && j = -2:0.5:12) Needs to be two nested loops: for i = 2:0.5:15 for j = -2:0.5:12

3 dagen ago | 1

Answered

Homework help.(User defined functions )

Hint: See these functions: doc size doc isequal doc error

Homework help.(User defined functions )

Hint: See these functions: doc size doc isequal doc error

3 dagen ago | 0

| accepted

Answered

trouble understanding for loops

The first problem is getting the input from the user. This assigns a char string to pv: pv=('What was your original mortgage v...

trouble understanding for loops

The first problem is getting the input from the user. This assigns a char string to pv: pv=('What was your original mortgage v...

4 dagen ago | 0

Answered

OR statement in a while Loop

Change to AND: while ((playerhp > 0) && (enemyhp > 0)) I.e., you only do the while loop when both hp are positive. It eit...

OR statement in a while Loop

Change to AND: while ((playerhp > 0) && (enemyhp > 0)) I.e., you only do the while loop when both hp are positive. It eit...

4 dagen ago | 0

| accepted

Answered

Fastest way to find the row number containing the most amount of black pixels in a gray-scale image?

[~,row_blackPix] = max(sum(image <= 20,2))

Fastest way to find the row number containing the most amount of black pixels in a gray-scale image?

[~,row_blackPix] = max(sum(image <= 20,2))

4 dagen ago | 0

| accepted

Answered

Varying step size for RK Method?

The only variable that depends on a new n is h, so only recalculate h and then run your loop as is. Although if you want to make...

Varying step size for RK Method?

The only variable that depends on a new n is h, so only recalculate h and then run your loop as is. Although if you want to make...

4 dagen ago | 0

Answered

conversion from base 13 to IEEE 754

For the base 13 conversions: doc dec2base doc base2dec https://www.mathworks.com/help/matlab/ref/dec2base.html https://www.m...

conversion from base 13 to IEEE 754

For the base 13 conversions: doc dec2base doc base2dec https://www.mathworks.com/help/matlab/ref/dec2base.html https://www.m...

5 dagen ago | 0

Answered

Whats wrong with my code? Taylor series Approx with error

You probably just need an absolute value error = abs((true-s)/true)*100; %Percent Error Formula That being said, true and erro...

Whats wrong with my code? Taylor series Approx with error

You probably just need an absolute value error = abs((true-s)/true)*100; %Percent Error Formula That being said, true and erro...

5 dagen ago | 0

Answered

Functions and For Loops For Polynomials

Some guidance: 1) The sum=0 part needs to be moved outside the loop, prior to the loop starting. The way you have it the sum re...

Functions and For Loops For Polynomials

Some guidance: 1) The sum=0 part needs to be moved outside the loop, prior to the loop starting. The way you have it the sum re...

5 dagen ago | 1

| accepted

Answered

How can I randomly select a subset of logicals?

T = your logical trials vector n = 20; % number of trials to keep f = find(T); % find the location of the 1's f = f(randperm(...

How can I randomly select a subset of logicals?

T = your logical trials vector n = 20; % number of trials to keep f = find(T); % find the location of the 1's f = f(randperm(...

6 dagen ago | 1

| accepted

Answered

Custom help information on structure fields

See this discussion: https://www.mathworks.com/matlabcentral/answers/480829-what-is-the-best-way-to-insure-that-all-of-my-funct...

Custom help information on structure fields

See this discussion: https://www.mathworks.com/matlabcentral/answers/480829-what-is-the-best-way-to-insure-that-all-of-my-funct...

6 dagen ago | 2

| accepted

Answered

Error using * Matrix dimensions must agree.

Change this piv=A(i:i); to this piv=A(i,i); And change this fac=A(j:i)./piv; to this fac=A(j,i)./piv;

Error using * Matrix dimensions must agree.

Change this piv=A(i:i); to this piv=A(i,i); And change this fac=A(j:i)./piv; to this fac=A(j,i)./piv;

6 dagen ago | 0

Answered

how to print multiple variables with strings in between ?

You could use fprintf. E.g. >> a = 5; >> b = 7; >> fprintf("Variable a equals: %g\n",a); Variable a equals: 5 >> fprintf("V...

how to print multiple variables with strings in between ?

You could use fprintf. E.g. >> a = 5; >> b = 7; >> fprintf("Variable a equals: %g\n",a); Variable a equals: 5 >> fprintf("V...

6 dagen ago | 1

| accepted

Answered

Swapping last matrix columns

From your description, I don't see how your code works for anything other that inputs having two columns. I would guess that thi...

Swapping last matrix columns

From your description, I don't see how your code works for anything other that inputs having two columns. I would guess that thi...

6 dagen ago | 0

Answered

C/Fortran callback to MATLAB

Maybe this can give you the framework you need. I have made some assumptions about how things are connected. You pass in a cha...

C/Fortran callback to MATLAB

Maybe this can give you the framework you need. I have made some assumptions about how things are connected. You pass in a cha...

6 dagen ago | 0

| accepted

Answered

Common numbers between arrays

You could write some code using the intersect( ) function for this. E.g., the first result >> A = {[1,2,3], [3 4 5 6], [3 7 8 ...

Common numbers between arrays

You could write some code using the intersect( ) function for this. E.g., the first result >> A = {[1,2,3], [3 4 5 6], [3 7 8 ...

6 dagen ago | 1

| accepted