0
votes
0answers
14 views

Get a set of points from Fourier plot on Matlab?

I have a program that collects raw data and also does a Fourier transform to get complex numbers. When I feed the raw data into Matlab to do its own FFT, I can get a nice plot of power on frequency. ...
0
votes
0answers
33 views

normalize function -inf to inf to integrate to one.

I have a function of the probability distribution (method of k nearest neighbor). How I normalize this function , that the area under the graph is equal to unity. I mean it will make the prob from ...
0
votes
0answers
26 views

I was wondering if there was a way to plot a vector field and a 3d surface in the same window

I want to plot the vector field $$\textbf{F}(x, y, z) = \sin(xyz)\textbf{ i }+ x^2y\textbf{ j }+ z^2e^{x/5}\textbf{ k }$$ And the surface (part of elliptic cylinder) $$\textbf{r}(u, v) = u\textbf{ i ...
1
vote
0answers
29 views

How to find change points in a graph on matlab

I have a graph like this I need to find points at which sudden changes happening for the DPC Time Curve. We can observe that at time 20 and around 70 increase is happening. How to do this in Matlab. ...
1
vote
2answers
38 views

How to plot not only the result but also the derivatives of an ode using the ode45 function in Matlab?

I have already successfully run a code for the simulation of the deflection of beams under different loadings. I used the Matlab program and the ode45 solver for Initial value Problems and bvp4c ...
0
votes
1answer
49 views

Matlab Cropping Plots

I want to adjust the amount of whitespace that is shown when plots are generated. I found this command to do just that: ...
1
vote
1answer
47 views

How to draw contour lines (projections) on axis x or y with octave?

With the builtin function contour(x,y,z) of octave one can draw level curves where z remains constant. My question is how to draw contour lines on axis x or axis ...
2
votes
1answer
62 views

How to draw stick trefoil knot

http://commons.wikimedia.org/wiki/File:Stick_number_trefoil.png I am interested in plotting the stick trefoil knot. I don't know where to start. I am looking for equations or co-ordinates of ...
1
vote
1answer
204 views

How to draw a circular 3D plot in matlab

I want to plot this function in matlab : sin(4*x)*cos(4*y) on a disk This is how i proceeded : syms x y; f=@(x,y) sin(4*x)*cos(4*y); ezmesh(f,'circ') This method works with f=@(x,y) ...
0
votes
2answers
241 views

How to find (and plot) a probability distribution function?

I'm working on my biometrics course, and I have to plot a pdf (I think it means probability density / distribution function). Here is a sample pdf graph : Introduction to Biometrics page 5 , figure ...
0
votes
1answer
61 views

Plot recursive signal in Matlab

I need to create and plot this signal in matlab with 2000 points: x(n) = 0.6530 x(n-1) - 0.7001 x(n-2) + v(n) Where $x(-1)=x(-2)=0$ and $v(n) =$ white noise I ...
1
vote
2answers
71 views

Graphing a function f(x,y) on a restricted set of values for (x,y)

I'm having a hard time with this certain problem. Suppose that $S=\{(x,y): x^2 + y^2\leq 4\}$ and define $f:S\rightarrow\mathbb{R}$ as $f(x,y)=-x-2y-2y^2+cos(x\pi /4)$. How can we produce a (3d) ...
0
votes
2answers
77 views

Intuition behind log plotting

The two plots are the same, except the 2nd one has been log transformed on the y axis. Could I please draw your attention to what happens when Theta >0.65? After taking the log-lin plot it seems ...
0
votes
0answers
34 views

$\exp(1i * 2 * \pi * (1:K) / K)$ to create clockwise format.

I was reading the documentation of R about text. here in the example : ...
2
votes
2answers
4k views

Piecewise function plot in Matlab

Is it possible in Matlab to plot an even piecewise function like: $ f(x) = \begin{cases} 3t , 0 < t < \pi \\ -3t , -\pi \le t \le 0 \end{cases}$ which has a period of $2\pi$. I ...
0
votes
0answers
904 views

Plotting symbolic function using symsum

I'm attempting to plot the temperature distribution with respect to time. I found that the solution to the Heat Equation with initial temperature distribution of $f(x)=|x|$ on $[-\pi,\pi]$ is ...
0
votes
1answer
107 views

Matlab Math Help

Consider the curve traced by a point on the rim of a circle rolling along a straight line, a cycloid. If the cycloid were drawn in the xy-plane, then it could be described by the following position ...
-1
votes
1answer
162 views

Plot using surf/mesh command in GNU octave

I want to plot a 3D plane in GNU Octave using the surf/mesh command. I have following data e.g a= [ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17]; b= [ 0.001 ...
0
votes
1answer
878 views

How do I get MATLAB to use custom labels for data in plots? [closed]

By this I mean, I have data that I would like to plot but each data corresponds to a different drug (aripiprazole, olanzapine, quetiapine and risperidone) and I would like the name of the drug to be ...
1
vote
4answers
370 views

Plotting in maple/MATLAB

How do you plot the following parametric equation (equation of an ellipse) in the same graph $$ x = a\cos{t} $$ $$ y = b\sin{t} $$ with varying value of $a$ and $b$ in either maple or MATLAB ? ...
0
votes
0answers
33 views

what the best software to plot points in 3D space [duplicate]

I have 4 points in the Eculidean space, $p_{0}=(0,0,1000)$ , $p_{1}=(0,0,0)$ , $p_{2}=(1000,1000,0)$ and $c=(231,231,412)$ I want to mark these points in the 3D space and connect the points $p_{0}c$, ...
0
votes
2answers
4k views

MATLAB Plot vertical line

I have a system of equations, about 3 equations, that I need to plot that are dependent on 2 variables, R and z. But one of the equations is R={constant value}. ...
0
votes
2answers
140 views

Logistic Equation: Equilibrium

Given a differential equation, for example, a logistic curve, how do I determine the equilibrium points, graphically? Consider $$x'=ax\left(1-\frac{x}{b}\right)-\frac{x^2}{1+x^2}$$ It is clear that ...
2
votes
2answers
113 views

Matlab plot3 see-through element

I am plotting the following Stewart platform in Matlab using plot3 and fill3. The green line that I have marked in the red ...
0
votes
2answers
2k views

Plotting joint distribution of 2-D random variable

I have some data which is basically a list of order pair (X,Y) and I want to see the joint distribution of this 2-D random variable. Is there any tool that provide this facility. Does Matlab has this ...
0
votes
1answer
282 views

How to a plot a line for ax+by-c in MATLAB?

The title basically says it all. I'm doing an assignment and need to include a plot of my scatter and the line generated by linprog(). I ran ...
0
votes
2answers
201 views

Matlab coding help

I need to graph the following functions on MATLAB: x(t)=(3/2)sin⁡(2t); y(t)=(-4/√15)e^(-1/2 t) sin(√15/2 t)+2e^((-1/2 t) )cos⁡(√15/2 t); h(t)=x(t)+y(t). I have the data points for this functions. I ...
0
votes
1answer
181 views

How to do I this linear least- squares problem?

This is what i am given: $y=[3, 5, 5, 8, 10, 12, 15, 16, 18, 19]$ and $t=[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]$ experimental data Solve x=A\b Thanks got it
0
votes
1answer
10k views

How to use polyfit() function in Matlab?

First of all i am new to Matlab, and not sure whether to use polyfit or something else for my problem. I plotted a graph with the following matlab code: ...
1
vote
1answer
1k views

Making sense out of plotting 3D graphs in octave/matplotlib

Recently I have a few times I wanted to plot 3D graphs in some applications (tried matplotlib and octave), noticing similar syntax, but I don't understand what it does so its hard to modify it ...
2
votes
2answers
1k views

What does the Matlab loglog plots do that is useful?

If there is a exponential relationship $y = e^x$ and we take the logarithm of this we can see a linear relationship $\ln (y) = x$. So we could plot the logarithm of the y-axis values against the x ...
0
votes
1answer
302 views

How to plot graph y=1/x or y=x^2

I am using Octave but I think it applies to MatLab too, so I'm tagging this MatLab since there isnt a Octave tag When I do x=linspace(-5,5,25) y=1/x I get ...
1
vote
1answer
198 views

Weibull Distribution Behaving Weirdly?

I'm attempting to fit a cumulative Weibull curve to some psychophysics perception data. Basically, we're testing the subject's accuracy at a number of different motion speeds, and attempting to fit ...