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Yuji Zhang


Tufts University Medford

Active since 2011

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I'm a Ph.D. student working on nonlinear optics. I use Matlab to process experimental data and, the more complicated thing is, perform numerical simulation of light propagation based on partial differential equations.
Professional Interests: nonlinear optics

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display rescaled matrix as image: imagesc vs wcodemat
Hi I tried two ways to rescale a matrix and display as an image: imagesc and wcodemat. Worded well in Fig 1. But in figure 2:...

ongeveer 9 jaar ago | 0 answers | 0

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answers

Answered
number divided by vector
I think I figured out myself. Division is defined by multiplication. For any A, B, and C, A/B = C means A = B*C. Note ...

meer dan 9 jaar ago | 0

Question


number divided by vector
Hi everyone~ I divided a number by a vector and forgot to use ./ Why it didn't report error and gave me some result? What's the...

meer dan 9 jaar ago | 4 answers | 0

4

answers

Question


is x' * x faster than x.^2 (x is a vector)
Hi~ Somebody recommended me to use x' * x. Is it faster than sum(x.^2) ? Any thoughts are appreciated. Thanks! [EDITED, s...

meer dan 9 jaar ago | 2 answers | 1

2

answers

Question


access values in dataset
hi In the results of lm = LinearModel.fit(x, y) there is lm.Coefficients containing the coefficient values. E.g., >...

meer dan 9 jaar ago | 2 answers | 0

2

answers

Question


what does c(:).' mean? c should be a vector
Hi I saw this in Matlab document: function obj = DocPolynom(c) % Construct a DocPolynom object using the coefficients...

meer dan 9 jaar ago | 2 answers | 0

2

answers

Question


waterfall appear to be out of box
Hi everyone, One waterfall plot appears that the curve are for outside the axis range. See this... Does anyone know how to fi...

bijna 10 jaar ago | 0 answers | 0

0

answers

Question


how to see the script of build-in function?
Hi all~ I put "edit sum" in the command line. And I only saw the notes about it (begin with %). How can I see the script of t...

ongeveer 10 jaar ago | 1 answer | 0

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answer

Question


reverse of fnval: evaluate the variable for given value of function
Hi everyone~ See the picture. The blue dots are my data. I want to find out at what x values the function drop to -20 (red ci...

meer dan 10 jaar ago | 1 answer | 0

1

answer

Question


curve fitting: how to get the fitting curve?
Hi everyone~ I did some curve fitting using curve fitting toolbox. But I don't know how to get the fitting curve. Can somebo...

meer dan 10 jaar ago | 1 answer | 0

1

answer

Question


about axis ticks: how to set 10 ticks with 5 labels?
Hi everyone, I want the axis to have ticks at 1:1:10, and tick labels only at 2:2:10 Anybody know how to do this? I tri...

meer dan 10 jaar ago | 1 answer | 0

1

answer

Question


figures got chopped when saved using "print"
Hi everyone~ I plot some figures, and save them to .tif file using "print" But it often got chopped. I use the code ...

meer dan 10 jaar ago | 0 answers | 0

0

answers

Question


multiple fittings in comparison in curve fitting toolbox
Hi everyone~ I'm using the curve fitting toolbox, for curve fitting, of course. I couldn't figure out how to show multiple...

meer dan 10 jaar ago | 0 answers | 0

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answers

Question


-v7.3 switch
Hi everyone~ I had problem saving a large variable (It's a cell. I think the problem is it's very large) The message is th...

meer dan 10 jaar ago | 1 answer | 1

1

answer

Question


loss of details using "print"
Hi everyone~ I was trying to plot some nice graphs. I tuned everything. It shows what I want in the Matlab plot window. But w...

meer dan 10 jaar ago | 1 answer | 0

1

answer

Question


pcolor - how to smooth
Hi everyone~ I'm plotting some contour map (x, y, z) If I use Origin, it does some nice smoothing. In Maltab, using ...

meer dan 10 jaar ago | 3 answers | 0

3

answers

Question


why definition of sine transform is not consistent with FFT?
<<https://lh4.googleusercontent.com/-QiXTlOnPnxE/UhRwYWPguoI/AAAAAAAAAx0/h2iASWeaI18/w1027-h432-no/dst.jpg>> See the picture....

meer dan 10 jaar ago | 0 answers | 0

0

answers

Question


the size of plot using "print"
Hi everyone~ I have a question about saving plot as pictures. I heard of the Oliver Woodford code but still want to check wi...

bijna 11 jaar ago | 0 answers | 0

0

answers

Question


genvarname -> Index exceeds matrix dimensions.
Hi everyone~ I have a quite stupid question here. genvarname doesn't work here, like this: >> vname = genvarname ('aaa'...

bijna 11 jaar ago | 1 answer | 0

1

answer

Question


manually run ode45 step by step - and impose filter to the half-way solution
Hi everybody~ I'm solving a ode: %% code 1 t = [tt1 tt2 tt3 ... tt100]; [t, y] = ode45(@equation, t, y1, optio...

bijna 11 jaar ago | 1 answer | 0

1

answer

Question


how to create customized curve ( only know the shape )
<<https://lh5.googleusercontent.com/-carEAOQXYm4/UcA2uOb251I/AAAAAAAAArQ/gBZKnJAQ8_o/w356-h463-no/curve.jpg>> Hi everyone~ ...

bijna 11 jaar ago | 3 answers | 0

3

answers

Question


about gradient and diff
The help of my matlab says: (in article "gradient -Gradient vector of scalar function") -If x is a scalar, gradient(f,x) = ...

bijna 11 jaar ago | 1 answer | 0

1

answer

Question


doing derivative using diff(Y)/dT makes the vector shorter
Hi everybody, I'm doing derivative of a curve Y-T I think it's: T = linspace(-t, t, n); Y = somefuction; dT = T(2)-T(1...

bijna 11 jaar ago | 3 answers | 0

3

answers

Question


syntax of handle: f = @(X)find(X);
Hi everyone~ I'm learning about use handle. The usual syntax is h = @FuncName But I also saw an example of f = @(X)find(X...

bijna 11 jaar ago | 2 answers | 0

2

answers

Question


"find" function doesn't work
Hi~ I got a weird problem here. See the attached picture. "find" works for some values and doesn't for some others. It could a s...

meer dan 12 jaar ago | 1 answer | 0

1

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