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find corresponding y coordinates

Fri, 03 Jul 2009 18:13:35 -0700

I will try to explain what I am trying to do in more detail.

Basically I have a binary image (attached) and I would like to plot a parabola across the min y's for x=20:300 for example.

But there are several values at y=1 in the binary image at x=200 for example.

I did it point by point the following way but its not practical for 200 points.

x1=125;
x2=120;
x3=115;
x4=110;
x5=105;
x6=100;
x7=95;
x8=80;
x11=75;
x12=70;
x13=65;
x14=60;
x15=55;
x16=40;
x17=35;

[y1]=find(I(:,x1));
[y2]=find(I(:,x2));
[y3]=find(I(:,x3));
[y4]=find(l(:,x4));
[y5]=find(I(:,x5));
[y6]=find(Il(:,x6));
[y7]=find(I(:,x7));
[y8]=find(I(:,x8));
[y11]=find(I(x11));
[y12]=find(I(:,x12));
[y13]=find(I(:,x13));
[y14]=find(I(:,x14));
[y15]=find(I(:,x15));
[y16]=find(I(:,x16));
[y17]=find(I(:,x17));

y1=min(y1);
y2=min(y2);
y3=min(y3);
y4=min(y4);
y5=min(y5);
y6=min(y6);
y7=min(y7);
y8=min(y8);
y11=min(y11);
y12=min(y12);
y13=min(y13);
y14=min(y14);
y15=min(y15);
y16=min(y16);
y17=min(y17);

Once I have the points I use p=polyfit(xcoord,ycoord,2) to draw the parabola which is pretty straightforward.The only problem I am facing is to get the corresponding minimum y coordinates for given larger range of x.

Best regards,

Finding the corresponding y coordinates in a binary image matlab

Thu, 02 Jul 2009 21:19:57 -0700

Hi everyone,

Just wanted to know if there is a way to do this...

I have a binary image, an I would like to find the min corresponding y coordinates for a given range , say x=120:200;

[y1]=find(image(:,x1));
y1=min(y1);

I can do it manually for up to 10 coordinates but is there any way i can do it for a range of x values.

I tried the following:

x = 120:380';
[y1]=find(image(:,x));
y=max(y);

But I am getting an error every time...

Any suggestions would be greatly appreciacted.

Many thanks,

matlab help

Tue, 30 Jun 2009 23:19:19 -0700

any one help me
i not getting images
my code:
im=imread('123.jpg');
imshow(im);
row=sum(im')';
plot(row);

but i am getting image 123,but i am not getting the row matrix i plotted.

Mathlab Help

Tue, 30 Jun 2009 22:28:25 -0700

Hello sir,

I saw this useful page in net when i was searching for mathlab help. Sir, i have been using mathlab software for image processing. And now im having a problem when i recieve a task on drawing lines according to pixels. For example:

From To Number of pixels
1 2 2
1 5 3

line 1 is connected to line 2 with a line which consist of no. of pixels 2
line 1 is connected to line 5 with a line which consist of no. of pixels 3

sir, i have a problem in starting the source code for line connection. can u show me on how to come out with the source codes.
i will give a try with ur starting help to finish my task

thank you sir
Good Day

Regards,
Lina

AR:Autoregressive Estimation Model

Tue, 30 Jun 2009 11:11:31 -0700

Hi Dear
i am new to estimation modeling. i want to start from simple estimation model. i got a real data for time series of 18 values as mentioned below.i want to use Yule-Walker AR Estimator. i can get the [a,e] straight from a = aryule(x,p);[a,e] = aryule(x,p)or [a,e,k] = aryule(x,p), but i dont know how to further develop the programe and estimate next 11 values in time domain. my in put data is as following:

x=[0 0.3286 0.2775 0.1168 -0.0902 -0.2620 -0.3311 -0.2701 -0.1030 0.1049 0.2720 0.3328 0.2634 0.0908 -0.1176 -0.2804 -0.3340 -0.2575];

can i request some one to help/guide me in developing the programme, please.

kind regards

Naveed

Problem with Transparency

Mon, 29 Jun 2009 05:23:10 -0700

Hello all,

I'm having a problem, would like to know if someone can help me.
I have a GUI that plot in the same axes plenty of plots. I'm constructing a vector to create a polygon, to use the patch function and show the desired area of the plot this way.

But the problem is, when I use transparency one of the lines that I have plotted simply disappear. When the facealpha is 1 (opaque), I don't have this problem.

Any idea how can I solve it?

Code I'm using:

patch(X_Vector, Y_Vector, 'r')
h= findobj(gca, 'Type', 'patch');
set(h,'LineWidth',1.15)
set(h,'FaceColor', 'r', 'EdgeColor', 'r', 'facealpha', .22);

thanks in advance!

greets,
Leonardo

pixels

Sat, 27 Jun 2009 03:08:14 -0700

i dont know how to do this: i need to fill all pixels with white color that are higher of some value like 50.any help.what command anything that will help

willing pay for help setup the simulink program!!pls contact me

Fri, 26 Jun 2009 10:01:00 -0700

pls contact me on my email alviss_cheah@yahoo.com.sg for this i will pay $200...any question can send a email to ask me...thx your help

To derive the following model curve using Matlab / Simulink using the following variables:

Aorta Diameter during Diastolic, AoD=23.22 mm
Aorta Diameter during Systolic, AoS =25.22 mm
Systolic Pressure, PS=133 mmHg
Diastolic Pressure, PD=81 mmHg
Stroke Volume, SV=52 ml
Ejection Time, ts =0.29 ms
Pulse Pressure, PP=PS-PD = 133 – 81 = 52
AorticStrain=(AoS-AoD)*100/AoD = 8.6133
AorticStiffness=[log(PS/PD)]/[(AoS-AoD)/AoD] = 5.7574
AorticDistensibility=2*AorticStrain/PP = 0.3313
Heartrate = 1/T = 60/73 = 82.19

Aim:
The model should output curves of similar shapes, but with different variables input, the graph should be automatically be generated out containing the different details.
In short, once the basic simulink model is functional, consecutive inputs with different datas should generate out different curves without making much of a changes to the model.

Blood Pressure Model

Fri, 26 Jun 2009 09:15:11 -0700

Hi People!! I am wondering if anyone is able to help me generate out a model of an arterial pressure waveform using matlab simulink software, a similar example of such a waveform can be found at :
http://www.bmt.tue.nl/opleiding/ogo/0304/3ejaar/3.html5.jpg
or
http://www.feec.vutbr.cz/EEICT/2004/sbornik/03-Doktorske_projekty/01-Elektronika/09-lahvo.pdf >>>> similar to that as of Figure 3.

The model should output curves of similar shapes, but with different variables input, the graph should be automatically be generated out containing the different details.
In short, once the basic simulink model is functional, consecutive inputs with different datas should generate out different curves without making much of a changes to the model.

To derive the following model curve using Matlab / Simulink using the following variables:
Aorta Diameter during Diastolic, AoD=23.22 mm
Aorta Diameter during Systolic, AoS =25.22 mm
Systolic Pressure, PS=133 mmHg
Diastolic Pressure, PD=81 mmHg
Stroke Volume, SV=52 ml
Ejection Time, ts =0.29 ms
Pulse Pressure, PP=PS-PD = 133 ? 81 = 52
AorticStrain=(AoS-AoD)*100/AoD = 8.6133
AorticStiffness=[log(PS/PD)]/[(AoS-AoD)/AoD] = 5.7574
AorticDistensibility=2*AorticStrain/PP = 0.3313
Heartrate = 1/T = 60/73 = 82.19

Thank you~ =)
You kind attention would be greatly appreciated.

binary integer prog with n-dimensional matrices

Fri, 26 Jun 2009 05:43:51 -0700

Hello,

I'm working on some binary integer programming problem. For simple problems these are of course easily solved using Matlab's bintprog function. However, my question is whether it is possible to somehow solve binary integer problems with more dimensions?

Of course it is possible to solve the problem by translating it to a one-dimensional problem, e.g. translate [x11 , x12 ; x21 , x22] to [x11 , x12 , x21 , x22], solve using bintprog and then translate back to 2x2. However, does anyone know if there's a more direct solution to this problem in matlab?

Thanks a lot!

Richard

how to accelerate simulink?

Wed, 24 Jun 2009 10:08:01 -0700

Hello people,

i'm working on simulink with real time camera, i wrote embedded matlab code with loops that run's on the frame matrix and this makes a delay in my real time camera.

do you have any suggestion how to make my webcam processing more live and with less delay.

thanks for your suggestion
Aviv.

how to convert matlab code to simulink?

Wed, 24 Jun 2009 09:53:13 -0700

Hello people,
I'm a new user of Simulink.
i wrote an algo' for pupil detection in matlab, now i want to convert this code to simulink code because i want use my algo on real time camera.
in my algo i'm using "BWlabel","Edge Detection" of matlab, i know that in simulink there is special blocks of "BWlabel" and "Edge Detection",
but if i'll use it i'll need to break down my matlab code into a large number of embedded matlab blocks, i'm looking for a way to avoid this action.

thank you for your suggestion,
Aviv.

small matrix question

Tue, 23 Jun 2009 20:32:53 -0700

Sorry for the simplicity of this question. If I have two matrices, one 1000 cells long, the other 4.5 million long. I want to multiple them to create a third matrix 4.5 million cells long, where the first cell of the first matrix multiplies the first 4500 of the second matrix, the second of the first matrix by the next 4500 of the second matrix etc. I am using a for loop but it is taking really long, is there a faster way?
thanks

about fmincon

Sun, 21 Jun 2009 04:43:15 -0700

hello;

I have a problem with the usage of 'fmincon'. I know that the objective function(let's name it objfun) of 'fmincon' should be written explicitly in another m file if i want to find the minimum value of objfun. But now, my objective function inludes for-loop, and the argument, at which i want to implement fmincon, is inclued in the for-loop, i.e. the objfun can't be written explicitly.

What can i do to handle it? do i need to do the program of minimizing myself since fmincon can't deal with it??

Thanks a lot...

i help your matlab problems

Wed, 17 Jun 2009 09:13:23 -0700

i am doing matlab projects,problems and assignments. pls check my website to get detailed information about my related works or write me to ask about your problem.

www.matlabexperts.com

serkan@matlabexperts.com

matlab

Wed, 17 Jun 2009 06:59:14 -0700

ihi..
ihave problems:
1. how to plot polynomial function from gui to axes?
2. can the axes read as image or jpg?

please help me, cz i am beginner in matlab programing
thank u

Program for Newton Raphson Method in Matlab

Wed, 17 Jun 2009 02:29:39 -0700

Hi,

I am trying to solve the following equation by Newton Raphson Method in Matlab

f(x)=Ks*log(x/x0)+x-x0-kt = 0

Where, x varies with time t; and x0 is the value of x at time t=0
x0, Ks and k are known constants

I need the values of x at different t values;
--
Any help will be highly apriciated.

Please Help with a Matlab problem

Tue, 16 Jun 2009 13:06:38 -0700

Hi!

I have an exam in a couple of days concerning Matlab, and the teacher gave us a couple of examples. And there is one problem that I have no idea how to resolve it in matlab. If you can, please help me with a solution in Matlab. Thank you in advance. Here is the problem:

"In the attempt of solving the equation of the radiative transfer in semi-infinite atmospheres, the non-lineary equation omega0 = 2k/(log((1+k)/(1-k))) can be found, where the number omega0 is between (0,1) is called albedo. Prove that a fixed omega0, if k is a root, so if -k and that there is only one root k between (0,1). For omega0=0.25,0.50,0.75, find the corresponding pozitive roots."

Pubmed Help

Tue, 16 Jun 2009 09:17:01 -0700

Can someone please help me with the syntax in getting a gds file from PubMed into Matlab as an array

edge density

Tue, 16 Jun 2009 09:15:43 -0700

i found edges in pictures by using canny method.then found that edge density by using matrix 3×3 and computing pixels.i've got a picture similar to one gotten from canny method.
on the picture is audience and the field.field is black.audience is somewhat gray.now i need to combine or merge that block of pixels that represents the audince and show how much percentage of the image is audience
any ideas?heeelp please

coloring a grid

Fri, 12 Jun 2009 07:27:17 -0700

Hi all,

I have a bunch of lat/long coordinates that I want to put into a grid that corresponds to a section of coast off a continent. I need to be able to color the grid (separated into 2.5x2.5 degree cells) based on the number of 'hits' each cell gets (ie if a lat/long coord fits into a cell then that is a hit).

Is there any easy way to do this? I was thinking just writing a loop that goes through the coordinates and adds one to the appropriate cell in an array representing the grid but I'm lost as to how to graph that. Being able to impose a coastline on it would be great too (I know matlab has shape files for each continent anyways..)

Thanks in advance for any help.

How to read mixed data from a file

Thu, 11 Jun 2009 10:05:22 -0700

How do I read mixed numeric and char data into MATLAB?

I have a file containing one column of data that looks something like this but much longer:

-.3453
-.4430
.13499
A
.9342

Mixed in with the numbers are these random "A"s. I want to read in the file and replace the "A"s with a number at the same location from a different file.

Femlab

Wed, 10 Jun 2009 14:11:42 -0700

Hi guys,

May I get help in using Femlab?

I have a system of reaction-diffusion equations which are

u_{t}=D_{1} u_{xx}+f(u,v)

v_{t}=D_{2} v_{xx}+g(u,v)

I solved it using Femlab for 2D.

My question is: How can I get animation for both

and

altogether in one animated graph?

I have just got animated graph for only one of them.

Any suggestions will be highly appreciated.

Thank you in advance.

RainyCloud

random Number with different seed.

Tue, 09 Jun 2009 16:14:06 -0700

I am able to generate gaussian random nos. in Matlab using rand; function but I need to change the seed. According to my requirment, c++ code is using

rand((int)time(NULL) + (int)getpid())

How am I going to do this in matlab.

Can Matlab give commands to the Windows command window?

Fri, 05 Jun 2009 11:43:11 -0700

(Repetative phrasing, I know, but not redundant :) )
Hello,
I'm a bit new to Matlab and programming and I'm curious if I can use a Matlab function or script to give commands to other programs through the Windows command line. The goal is to write a Matlab function (or script, eithe will work I think) that can use the windows command line to operate the NDFD GRIB2 Decoder program. I want to be able to call the function in matlab by giving it the raw GRIB file name, then have the function send the raw file through the GRIB decoder to turn the GRIB info into a text file, then have the function import the text file to Matlab and manipulate the info. I have done each of these steps separately, but I was curious if anyone knows if there is a way to sort of interface Matlab with the command window. I've got Windows XP.
Thanks!
-Khiya