Community Profile

# Yuji Zhang

### Tufts University Medford

Active since 2011

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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Question

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:...

7 years ago | 0 answers | 0

### 0

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 ...

7 years 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...

7 years ago | 4 answers | 0

### 4

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...

7 years ago | 2 answers | 1

### 2

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., >...

8 years ago | 2 answers | 0

### 2

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...

8 years ago | 2 answers | 0

### 2

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...

8 years ago | 0 answers | 0

### 0

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...

8 years ago | 1 answer | 0

### 1

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...

8 years ago | 1 answer | 0

### 1

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...

8 years ago | 1 answer | 0

### 1

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...

8 years ago | 1 answer | 0

### 1

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 ...

8 years ago | 0 answers | 0

### 0

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...

8 years ago | 0 answers | 0

### 0

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...

8 years ago | 1 answer | 0

### 1

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...

8 years ago | 1 answer | 0

### 1

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 ...

8 years ago | 3 answers | 0

### 3

Question

why definition of sine transform is not consistent with FFT?

9 years ago | 0 answers | 0

### 0

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...

9 years ago | 0 answers | 0

### 0

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'...

9 years ago | 1 answer | 0

### 1

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...

9 years ago | 1 answer | 0

### 1

Question

how to create customized curve ( only know the shape )

9 years ago | 3 answers | 0

### 3

Question

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

9 years ago | 1 answer | 0

### 1

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...

9 years ago | 4 answers | 0

### 4

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...

9 years ago | 2 answers | 0