Hic sunt dracones!

PROFESSIONAL: Physician (M.D.): Diplomate of the American Board of Internal Medicine; M.Sc. Biomedical Engineering: Instrumentation, Signal Processing, Control, System Identification, Parameter Estimation

NON-PROFESSIONAL: Amateur Extra Class Amateur Radio Operator; Private Pilot, Airplane Single Engine Land, Instrument Rating Airplane; Gamer

NOTE: I do not respond to emails or personal messages, unless they are about my File Exchange contributions.

Answered

Step response with initial condition

To set the step amplitude to 10, try this: k=0.2; t2=400; s = tf('s'); u_del=(0.0022*k*(s+0.06931)*(s^2+0.4852*s+0.1492))/(...

Step response with initial condition

To set the step amplitude to 10, try this: k=0.2; t2=400; s = tf('s'); u_del=(0.0022*k*(s+0.06931)*(s^2+0.4852*s+0.1492))/(...

alrededor de 1 hora ago | 0

Answered

Plotting date (number) on x-axis

It is necessary to be creative with the plot and the tick labels. Try this: DL = load('april.mat'); ex1 = DL.ex1; Q1 = ex...

Plotting date (number) on x-axis

It is necessary to be creative with the plot and the tick labels. Try this: DL = load('april.mat'); ex1 = DL.ex1; Q1 = ex...

alrededor de 16 horas ago | 0

| accepted

Answered

Error in using syms

Remove the single quotes, define ‘x’ as ‘x(t)’, and define ‘Dx’ (and ‘D2x’ if you want to), explicity: syms x(t) t s X F Dx ...

Error in using syms

Remove the single quotes, define ‘x’ as ‘x(t)’, and define ‘Dx’ (and ‘D2x’ if you want to), explicity: syms x(t) t s X F Dx ...

alrededor de 21 horas ago | 1

| accepted

Answered

How can I delete rows with periodically in an excel file with matlab?

It depends on what the array is. To delete every other row (if ‘Array’ is your matrix): NewArray = Array(1:2:end,:); there...

How can I delete rows with periodically in an excel file with matlab?

It depends on what the array is. To delete every other row (if ‘Array’ is your matrix): NewArray = Array(1:2:end,:); there...

1 día ago | 0

Answered

using the vertical bars in calculation

I am not sure what you are asking. Perhaps the abs function?

using the vertical bars in calculation

I am not sure what you are asking. Perhaps the abs function?

1 día ago | 0

| accepted

Answered

How can I plot sequential data of a matrix

Try this: A = [0 329.62 0.01 329.61 0.014 329.60 0.2 329.59 0.00 329.63 0.05 329....

How can I plot sequential data of a matrix

Try this: A = [0 329.62 0.01 329.61 0.014 329.60 0.2 329.59 0.00 329.63 0.05 329....

1 día ago | 1

| accepted

Answered

No numeric data plot x axis

Try this: syms X L L = 16; Y = 1 + 2*X; figure fplot(Y, [0 L]); .

No numeric data plot x axis

Try this: syms X L L = 16; Y = 1 + 2*X; figure fplot(Y, [0 L]); .

1 día ago | 0

Answered

How can we fill a region defined by a implicit function?

I am not certain what you want. Try this: f=@(x,y) sin(x).*sin(y)-0.5; figure fp1=fimplicit(f,[-10,10,-10,10]); hold o...

How can we fill a region defined by a implicit function?

I am not certain what you want. Try this: f=@(x,y) sin(x).*sin(y)-0.5; figure fp1=fimplicit(f,[-10,10,-10,10]); hold o...

1 día ago | 0

| accepted

Answered

Keep y value below certain value in a loop

Try something like this: x = linspace(0, 5*pi, 250); Capacity = 0.7; limit_y = @(y,Capacity) (y<0).*0 + (y>Capacity).*Capaci...

Keep y value below certain value in a loop

Try something like this: x = linspace(0, 5*pi, 250); Capacity = 0.7; limit_y = @(y,Capacity) (y<0).*0 + (y>Capacity).*Capaci...

2 días ago | 0

Answered

Error converting from sym to double: Unable to convert expression into double array

Try this to create ‘T’ as a vector: n = 5 % Define ‘n’ syms T T = sym('T', [1 n]) produc...

Error converting from sym to double: Unable to convert expression into double array

Try this to create ‘T’ as a vector: n = 5 % Define ‘n’ syms T T = sym('T', [1 n]) produc...

2 días ago | 0

Answered

How to calculate the area between two curves separately based on being below or above.

Try something like this: t = linspace(0, 10*pi, 500); % Create Data y1 = exp(-0.1*t) .* si...

How to calculate the area between two curves separately based on being below or above.

Try something like this: t = linspace(0, 10*pi, 500); % Create Data y1 = exp(-0.1*t) .* si...

2 días ago | 0

| accepted

Answered

making matrix of matrices of specific inputs

Try this: for a = 1:numel(length_x11) % for b = 0:9 i11 = length_x11(a); j21 = length_y21(a); ...

making matrix of matrices of specific inputs

Try this: for a = 1:numel(length_x11) % for b = 0:9 i11 = length_x11(a); j21 = length_y21(a); ...

2 días ago | 0

| accepted

Answered

Filled 2D plot

My apologies for the delay. I was working on other things most of today. ‘However, to make the data more concise, I am try...

Filled 2D plot

My apologies for the delay. I was working on other things most of today. ‘However, to make the data more concise, I am try...

2 días ago | 0

| accepted

Answered

Unrecognized function or variable 'visadevlist'.

The visadevlist function requires the Instrument Control Toolbox.

Unrecognized function or variable 'visadevlist'.

The visadevlist function requires the Instrument Control Toolbox.

3 días ago | 0

| accepted

Answered

Multiple griddata calls into a single one (same grid)

The arrayfun function is significantly slower than an explicit loop, at least in my experience. I would just do something lik...

Multiple griddata calls into a single one (same grid)

The arrayfun function is significantly slower than an explicit loop, at least in my experience. I would just do something lik...

3 días ago | 0

Answered

Split Table data based on Day Names

Try this: C1 = readcell('Sample.csv'); [G,ID] = findgroups(C1(:,6)); % Idx = [4 2 6 7 5 1 3]; ...

Split Table data based on Day Names

Try this: C1 = readcell('Sample.csv'); [G,ID] = findgroups(C1(:,6)); % Idx = [4 2 6 7 5 1 3]; ...

3 días ago | 0

| accepted

Answered

How do I fit a Sinuscurve to my Data-Function, WITHOUT Cftool?

See if the approach in Curve fitting to a sinusoidal function will do what you want. It uses only core MATLAB functions, no to...

How do I fit a Sinuscurve to my Data-Function, WITHOUT Cftool?

See if the approach in Curve fitting to a sinusoidal function will do what you want. It uses only core MATLAB functions, no to...

3 días ago | 0

Answered

How do I plot fourier transform signals in Matlab

f = @ (t) exp(-abs(t)).*cos(20*t); figure fplot(f) for the Symbolic Math Toolbox, this becomes: syms t f(t) = exp(-abs(...

How do I plot fourier transform signals in Matlab

f = @ (t) exp(-abs(t)).*cos(20*t); figure fplot(f) for the Symbolic Math Toolbox, this becomes: syms t f(t) = exp(-abs(...

4 días ago | 0

| accepted

Answered

How to remove spurious lines?

Sort ‘velocity’: [velocity, idx] = sort(velocity); figure plot3(Freqs,velocity,filtered(idx)) ylim([-2 0]) xlim([2.5 15]...

How to remove spurious lines?

Sort ‘velocity’: [velocity, idx] = sort(velocity); figure plot3(Freqs,velocity,filtered(idx)) ylim([-2 0]) xlim([2.5 15]...

4 días ago | 0

| accepted

Answered

Unknown variable complex equation

I ahve no idea what ‘Cp’ does here. Otherwise: gamma = 1.4; prat = @(Me,gamma) ((1+(gamma-1)/2.*Me.^2).^(gamma/(gamma-1)))...

Unknown variable complex equation

I ahve no idea what ‘Cp’ does here. Otherwise: gamma = 1.4; prat = @(Me,gamma) ((1+(gamma-1)/2.*Me.^2).^(gamma/(gamma-1)))...

4 días ago | 0

| accepted

Answered

solve equation : Empty sym: 0-by-1

The Symbolic Math Toolbox may not be appropriate for this problem. Try this: freq = linspace(10*1e3, 31*1e6,100); w = 2*pi...

solve equation : Empty sym: 0-by-1

The Symbolic Math Toolbox may not be appropriate for this problem. Try this: freq = linspace(10*1e3, 31*1e6,100); w = 2*pi...

4 días ago | 0

Answered

plotting 2 variables as they change with respect to one another

The solution is to subscript ‘A’. Try this: gamma = 1.4; %M=1.53 Mv = (0.1:0.01:2.19); for k1 = 1:numel(Mv) M = Mv(...

plotting 2 variables as they change with respect to one another

The solution is to subscript ‘A’. Try this: gamma = 1.4; %M=1.53 Mv = (0.1:0.01:2.19); for k1 = 1:numel(Mv) M = Mv(...

4 días ago | 0

Answered

Divide matrix in subgroups

The mat2cell function will likely do what you want. Note that assigning each matrix to a different variable is not advisable....

Divide matrix in subgroups

The mat2cell function will likely do what you want. Note that assigning each matrix to a different variable is not advisable....

4 días ago | 0

| accepted

Answered

Suggestions for financial simulation

That is an interesting problem! Use your favourite seach engine (I prefer DuckDuckGo) and search on: financial simulations usin...

Suggestions for financial simulation

That is an interesting problem! Use your favourite seach engine (I prefer DuckDuckGo) and search on: financial simulations usin...

4 días ago | 0

Answered

How do I extract the amplitude and the frequency from a sine function?

Use the fft function. Calculated, interpreted, and plotted correctly, it will give all that information.

How do I extract the amplitude and the frequency from a sine function?

Use the fft function. Calculated, interpreted, and plotted correctly, it will give all that information.

4 días ago | 0

Answered

Returning to a function and changing variables if ans is false?

I would do something like this, and treat it as an optimization (specifically root-finding) problem, returning the value of ‘dRo...

Returning to a function and changing variables if ans is false?

I would do something like this, and treat it as an optimization (specifically root-finding) problem, returning the value of ‘dRo...

4 días ago | 0

Answered

How to reduce the size of a graph to see the title and a legend that are not displayed?

Try something like this: figure plot( ... ) title( ... ) legend( ... ) pos = get(gcf, 'Position') set(gcf, 'Position',pos...

How to reduce the size of a graph to see the title and a legend that are not displayed?

Try something like this: figure plot( ... ) title( ... ) legend( ... ) pos = get(gcf, 'Position') set(gcf, 'Position',pos...

5 días ago | 0

Answered

Date time conversion problem

The posted code has errors. Try this: A = ['2015-01-01T19:00:00+0100' '2015-01-01T20:00:00+0100']; dates_extracted...

Date time conversion problem

The posted code has errors. Try this: A = ['2015-01-01T19:00:00+0100' '2015-01-01T20:00:00+0100']; dates_extracted...

5 días ago | 0

Answered

overlapping two contours and defining specific lines to be compared

See the contour documentation section on levels for details. To plot contours at 18°C, that would plot as: contour(X,Y,Z, [1 ...

overlapping two contours and defining specific lines to be compared

See the contour documentation section on levels for details. To plot contours at 18°C, that would plot as: contour(X,Y,Z, [1 ...

5 días ago | 1

| accepted

Answered

Plotting errorbar on a set of data

I do not see ‘B’ anywhere. With ‘A’ as the matrix in the post, try this: Amean = mean(A(:,2:end),2); Astd = std(A(:,2:end)...

Plotting errorbar on a set of data

I do not see ‘B’ anywhere. With ‘A’ as the matrix in the post, try this: Amean = mean(A(:,2:end),2); Astd = std(A(:,2:end)...

5 días ago | 0