Answered

fit 2nd order differential equation parameters to data

The problem appears to be not allowing the intial conditions to be estimated as parameters as well as the initial value of ‘a_m’...

fit 2nd order differential equation parameters to data

The problem appears to be not allowing the intial conditions to be estimated as parameters as well as the initial value of ‘a_m’...

5 days ago | 0

| accepted

Answered

Using solve to find intersection points

It’s as simple as it looks — syms x f(x) = exp(-x^2) g(x) = sym(0.8) xi = solve(f == g) xi_vpa = vpa(xi) .

Using solve to find intersection points

It’s as simple as it looks — syms x f(x) = exp(-x^2) g(x) = sym(0.8) xi = solve(f == g) xi_vpa = vpa(xi) .

5 days ago | 0

| accepted

Answered

How can I simplify the folllowing equation

One approach — syms x Eqn = 2*x^2 - 2*x*(2*x^2 - 1) + 2*x*(2*x*(2*x^2 - 1) - 2*x^2 + 1) - 1 Eqn = simplify(Eqn, 500) .

How can I simplify the folllowing equation

One approach — syms x Eqn = 2*x^2 - 2*x*(2*x^2 - 1) + 2*x*(2*x*(2*x^2 - 1) - 2*x^2 + 1) - 1 Eqn = simplify(Eqn, 500) .

6 days ago | 0

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Answered

How to plot data with two different X- axis in a single plot?

One option is to use the subplot function in a loop — Z = readtable('https://www.mathworks.com/matlabcentral/answers/uploade...

How to plot data with two different X- axis in a single plot?

One option is to use the subplot function in a loop — Z = readtable('https://www.mathworks.com/matlabcentral/answers/uploade...

6 days ago | 0

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Answered

translating and solving an equation with values of x and y known

In the third term, the square root is of the numerator only, not the entire expression, amd the denominator does not appear to h...

translating and solving an equation with values of x and y known

In the third term, the square root is of the numerator only, not the entire expression, amd the denominator does not appear to h...

6 days ago | 0

Answered

To determine whether the system is stable.

Welcome to the wonderful world of floating-point approximation error! See ‘Check’ and ‘Check_max’ for an illustration of the ...

To determine whether the system is stable.

Welcome to the wonderful world of floating-point approximation error! See ‘Check’ and ‘Check_max’ for an illustration of the ...

7 days ago | 1

| accepted

Answered

How to properly format a data table with fprintf?

In the numeric edit descriptors, the value to the left of the decimal is the field width (this includes all the numbers, the sig...

How to properly format a data table with fprintf?

In the numeric edit descriptors, the value to the left of the decimal is the field width (this includes all the numbers, the sig...

7 days ago | 0

Answered

Find which matrix row contains average minimum value

One approach — M = rand(288,365); AMV = mean(min(M)) % Average Minimum Value [val,idx] ...

Find which matrix row contains average minimum value

One approach — M = rand(288,365); AMV = mean(min(M)) % Average Minimum Value [val,idx] ...

7 days ago | 0

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Answered

trying to find theta

The Question lacks clarity. % plot mountain Mn_x = [0, 1000, 3014.8]; Mn_y = [0, 0, 616]; plot (Mn_x, Mn_y) hol...

trying to find theta

The Question lacks clarity. % plot mountain Mn_x = [0, 1000, 3014.8]; Mn_y = [0, 0, 616]; plot (Mn_x, Mn_y) hol...

7 days ago | 0

| accepted

Answered

Solve for x given y and plot

Depending on what you wan, either use fzero or interp1 — y = @(x) (2 * exp((2*x)/3)) - ((7*x.*exp((2*x)/3))/3); x = linspace(...

Solve for x given y and plot

Depending on what you wan, either use fzero or interp1 — y = @(x) (2 * exp((2*x)/3)) - ((7*x.*exp((2*x)/3))/3); x = linspace(...

7 days ago | 0

| accepted

Answered

Doubt in solving ODE45

It seems that ‘dis’ does not appear anywhere. L=20; v=20;%v (m/sec) T=L/v; tspan_1=[0:0.001:T];%time range y0_1=[0;0];...

Doubt in solving ODE45

It seems that ‘dis’ does not appear anywhere. L=20; v=20;%v (m/sec) T=L/v; tspan_1=[0:0.001:T];%time range y0_1=[0;0];...

7 days ago | 0

Answered

How do you plot a line of constant value on a surface plot?

See if contour3 or contour3m will do what you want. [X,Y,Z] = peaks(30); figure surf(X,Y,Z) hold on contour3(X,Y,Z,[1 1...

How do you plot a line of constant value on a surface plot?

See if contour3 or contour3m will do what you want. [X,Y,Z] = peaks(30); figure surf(X,Y,Z) hold on contour3(X,Y,Z,[1 1...

7 days ago | 0

Answered

How to properly create function for integration?

There are several problems with the posted code image. First, ‘z’ is not defined anywhere, and it is not an argument to ‘E_fu...

How to properly create function for integration?

There are several problems with the posted code image. First, ‘z’ is not defined anywhere, and it is not an argument to ‘E_fu...

7 days ago | 0

Answered

How can I plot the derivatives of the components of the solution to a system of ODEs?

The only way is to use al loop — tspan = [0 50]; z0=[0.01 0.01 0.01 0.01]; [t,z] = ode45(@(t,z) coupled(t,z), tspan, z0); ...

How can I plot the derivatives of the components of the solution to a system of ODEs?

The only way is to use al loop — tspan = [0 50]; z0=[0.01 0.01 0.01 0.01]; [t,z] = ode45(@(t,z) coupled(t,z), tspan, z0); ...

8 days ago | 2

| accepted

Answered

Cannot calculate integral function

If you want a numeric result, use vpaintegral (introduced in R2016b) instead of int. Not all expressions have analytic integral...

Cannot calculate integral function

If you want a numeric result, use vpaintegral (introduced in R2016b) instead of int. Not all expressions have analytic integral...

8 days ago | 0

| accepted

Answered

How to convert logarithmic to linear

If you have the Signal Processing Toolbox, use the db2mag function. If you do not have it: dB2mag = @(dB) 10.^(dB/20); ...

How to convert logarithmic to linear

If you have the Signal Processing Toolbox, use the db2mag function. If you do not have it: dB2mag = @(dB) 10.^(dB/20); ...

8 days ago | 0

Answered

Matlab Polar Plot Legend does not match with the plot

I cannot run that and I amm not certain what you are are plotting. Create a handle for each polarplot call: th = linspace(0, ...

Matlab Polar Plot Legend does not match with the plot

I cannot run that and I amm not certain what you are are plotting. Create a handle for each polarplot call: th = linspace(0, ...

8 days ago | 0

Answered

How to save output of double loop as a matrix?

Since ‘A’ is a matrix, save it as a cell array — for i=1:m for j=1:n A{i,j} = myfunction(...) end end .

How to save output of double loop as a matrix?

Since ‘A’ is a matrix, save it as a cell array — for i=1:m for j=1:n A{i,j} = myfunction(...) end end .

8 days ago | 1

| accepted

Answered

Shaded Standard Deviation Corridors

There are NaN values in ‘x’, ‘y’, and ‘sd’. This ia frequent cause of patch failures. Remove them and it works! Try this ...

Shaded Standard Deviation Corridors

There are NaN values in ‘x’, ‘y’, and ‘sd’. This ia frequent cause of patch failures. Remove them and it works! Try this ...

8 days ago | 1

| accepted

Answered

3D Sphere projection in Matlab

I worked on this for a while yesterday, without success. Today, I used a relatively straightforward approach that simply flips ...

3D Sphere projection in Matlab

I worked on this for a while yesterday, without success. Today, I used a relatively straightforward approach that simply flips ...

8 days ago | 1

Answered

How would I go about writing this equation in matlabs?

There are several options, depending on what you want to do. syms x p(x) = 1/(2*sqrt(sym(pi)))*exp(-(x-5)^2/4) figure f...

How would I go about writing this equation in matlabs?

There are several options, depending on what you want to do. syms x p(x) = 1/(2*sqrt(sym(pi)))*exp(-(x-5)^2/4) figure f...

9 days ago | 0

| accepted

Answered

How to save .mat file into hdf5 in matlab?

I have no recent experience with HDF5 files, however the h5write documentation for data indicates that it must be a numeric matr...

How to save .mat file into hdf5 in matlab?

I have no recent experience with HDF5 files, however the h5write documentation for data indicates that it must be a numeric matr...

9 days ago | 0

Answered

Error with plotting my function

It works if you give ‘f’ a vector to work with — f = @(x) 2.^x-5*x+2; %Given Function xaxis = [0:0.5:2]; ...

Error with plotting my function

It works if you give ‘f’ a vector to work with — f = @(x) 2.^x-5*x+2; %Given Function xaxis = [0:0.5:2]; ...

9 days ago | 2

| accepted

Answered

I am trying to plot an ellipse using a polarplot function.

The polarplot function requires the angular measure to be in radians. Change that in the polarplot call and it works. (The e...

I am trying to plot an ellipse using a polarplot function.

The polarplot function requires the angular measure to be in radians. Change that in the polarplot call and it works. (The e...

9 days ago | 0

| accepted

Answered

Am I using corrcoef correctly?

‘Am I using corrcoef correctly?’ Yes, except for squaring the result, and that will produce . H=log([0.01 0.02 0.03 0.04 ...

Am I using corrcoef correctly?

‘Am I using corrcoef correctly?’ Yes, except for squaring the result, and that will produce . H=log([0.01 0.02 0.03 0.04 ...

9 days ago | 0

| accepted

Answered

Converting a linear equation to decibel

The ‘theta’ vector likely needs to have more points, however that appears to be correct. I use a slightly different approach ...

Converting a linear equation to decibel

The ‘theta’ vector likely needs to have more points, however that appears to be correct. I use a slightly different approach ...

9 days ago | 0

| accepted

Answered

Sampling frequency and correct signal plotting

I believe this is simply an interaction of the sampling frequency and the signal frequency, typically referred to as ‘aliasing’....

Sampling frequency and correct signal plotting

I believe this is simply an interaction of the sampling frequency and the signal frequency, typically referred to as ‘aliasing’....

9 days ago | 0

| accepted

Answered

Creating new table from another table

There are several ways to do this, including using the findgroups function. A relatively efficient way is just to do the comp...

Creating new table from another table

There are several ways to do this, including using the findgroups function. A relatively efficient way is just to do the comp...

10 days ago | 1

| accepted

Answered

Amplitude detection in time series data

There are at least two functions you could experiment with, those being findchangepts and ischange. EDIT — (18 Sep 2021 at ...

Amplitude detection in time series data

There are at least two functions you could experiment with, those being findchangepts and ischange. EDIT — (18 Sep 2021 at ...

10 days ago | 0

| accepted

Answered

How to calculate mantissa of 0.5

I created a little utility function to calculate the mantissa and exponent of a floating-point number a while ago, for my own us...

How to calculate mantissa of 0.5

I created a little utility function to calculate the mantissa and exponent of a floating-point number a while ago, for my own us...

10 days ago | 0

| accepted