The Engineering Projects

continuous real time spatial resolution

I started this project on NI LabVIEW while ago and left it due to some problems that i needed to take care of.

I'm trying to read in real time from 4 analogue inputs in Arduino and display it over intensity graph on VI

I have a sensor mat that can detect pressure, I wrote my code through Arduino to send a high voltage from 4 digital pins each one at a time, and read from the 4 analogue pins in each time i send a high voltage to the sensor mat (surface).

my VI can read continuously and store in 2D array, but display over an intensity graph up to one time then stop processing the rest unless if i'm stopping the program then activated again.

what i want is: reading my data every time and the most important see the spatial resolution changes due to change the weights over this sensor mat. like detecting the position of the weight over the sensor mat and see it in real time.

i'm reading the data through a serial USB connection between the PC and Arduino, reading from VISA and store it in 2D array then try to display it.

in the attachment you'll fine a picture about what i mean by sending high voltage at a time and read from the analogue pins . also my VI that i'm trying to work on it from long time, but unfortunately i couldn't touch it for a while now.


looking for your knowledge and help.
[img]http://forums.ni.com/ni/attachments/ni/170/1006201/1/lab.JPG[/img]

Set white Frame to a Picture

I want to add a white frame with one Pixel thickness to a picture in order to separate particles from the image border. I need a gradient completely surrounding each particle, which isn't the case if they touch the image border.

I made a VI which reads an Image, and then makes an array filled with zeros in the dimensions of the picture plus two in each dimension. Then I convert that array into a picture which is two pixels bigger in x and y each than the input picture, and completely white.
Then I copy the first picture in the white one, with an offset of 1;1. This VI should put a white Frame onto my picture which it doesnt. Can somebody tell me what I did wrong?

Thanks for any help.

How to do strcmp in textboxes with Matlab

I would like to know how to compare strings between 2 textboxs in Matlab. Can someone please give some examples? Thank you in advantage.

How to call a function which is in another program MATLAB

I write this in my main program [code] [C,rows,cols,entries] = Matrix('C.txt')[/code] Matrix fuction is in another program Matrix.m and I want to call it.

I get this error :
[code]Undefined function or variable 'Matrix'. Error in (line 19) [C,rows,cols,entries] = Matrix'C.txt')[/code] Can you please tell me how to fix it ?

How can I find each max element of three matrices as new matrix?

Maybe the question is a little bit confused, I'll make an example below.

Let's say I have a 3 matrices a, b, c with same size. [code] a = [2, 5; 6, 9]; b = [3, 3; 8, 1]; c = [5, 5; 2, 7];[/code] How can I get the new matrix max with each max element in all three matrices?
[code]max = [5, 5; 8, 9][/code] I know I could create logical matrix like a>b and then do the math, calc it out, is there any other more efficient way to do it?

MATLAB App Designer non-Numeric data plotting

UIAxes in Matlab App designer does not support non-numeric data such as a graph plot, is there any alternative to do it inside UI framework?

[img]https://i.stack.imgur.com/Bgbxb.png[/img]

Reproducible results when creating random matrices across parallel calls in MATLAB

I want to create a number of random matrices, but they are really big to fit in memory, so I'd like to find a way to reproduce them across computers, so that when I need to send them to another machine, I'd just need to send the code. Here is how I want to do it:
[code]num_of_iters = 10; K = 200; for iter = 1:num_of_iters parfor j = 1:K R = make_random_R(iter,j,.....); % Do something end end[/code] What I'm worried about is the parfor loop, I need to be able to reproduce the random matrices no matter what the order of indices in the parfor is. So I decided to use a MATLAB stream for this:

Save the global stream
Create a new stream, set the seed and appropriate substream (which depends on iter and j)
Do the math
Put back the global stream
Here is my code (the variables n,p,R_type control how the random matrices are made, but they are not important, and K is the same variable as the one from above, I need it in the line substream_id = (iter - 1) * K + j;) :
[code]function [R] = make_random_R(iter,j,n,K,p,R_type) % Data as code % R_type: 'posneg' or 'normdist' % 1 <= iter <= 100 % 1 <= j <= K % K: Number of classifiers % n: Number of observations assert(strcmp(R_type,'posneg') || strcmp(R_type,'normdist'),'R_type must be posneg or normdist'); assert(iter >= 1,'Error: iter >= 1 not satisfied'); assert((1 <= j) && (j <= K),'Error: 1 <= j <= K not satisfied'); assert(K > 0,'Error: K > 0 not satisfied'); globalStream = RandStream.getGlobalStream; globalState = globalStream.State; stream=RandStream('mlfg6331_64','Seed',1); substream_id = (iter - 1) * K + j; stream.Substream = substream_id; RandStream.setGlobalStream(stream); switch R_type case 'posneg' q0=ceil(2*log(n)/0.25^2)+1; if (q0 < p) q = q0; else q = ceil(p/2); end R = randi([0 1],p,q); R(R == 0) = -1; case 'normdist' q = 2*ceil(log2(p)); R = normrnd(0,1,[p,q]); end RandStream.setGlobalStream(globalStream); globalStream.State = globalState; end[/code] Tried some code and here it is:
[code]>> iter = 2; >> j = 3; >> n=100; >> K=10; >> p=6; >> R_type = 'normdist'; >> for j=1:K j make_ran >> parfor j=1:K j make_random_R(iter,j,n,K,p,R_type) end Starting parallel pool (parpool) using the 'local' profile ... connected to 4 workers. ans = 7 ans = -0.3660 0.8816 1.1754 -0.4987 -1.8612 -0.3683 0.9504 -0.3067 -0.5156 -0.2383 -1.1661 0.3622 2.0743 -0.4195 0.5021 0.3954 0.2415 -0.4552 -0.0474 -0.1645 -0.1725 -0.4938 -0.2559 0.2188 1.0735 0.3660 0.1043 0.4403 -0.3166 1.1241 -1.0421 -1.4528 -0.4976 -0.7166 -1.1328 -2.0260 ans = 2 ans = -1.6629 0.0213 -1.8138 -0.4375 0.3575 -0.0353 0.6653 -1.2662 -0.3977 -0.6540 -1.2131 0.4858 0.3421 1.1266 -0.6066 -1.2095 1.5496 -0.9341 0.2145 0.7192 -2.2087 0.7597 -0.0110 -1.1282 -0.3511 -0.7305 -0.1143 0.0242 0.2431 -0.8612 0.5875 1.2665 -2.1943 -0.4879 0.0120 -1.1539 ans = 1 ans = -0.5300 2.4077 -0.3478 1.8695 -1.1327 -1.0734 -0.2540 -1.1265 0.3152 0.4265 1.2777 0.0959 0.5005 -0.7557 0.6194 1.5873 0.0961 -1.9216 0.7275 0.5420 -0.6237 -0.2228 0.8915 0.4644 0.8131 -0.1492 0.9232 0.8410 -0.0637 2.1163 -1.1995 0.2338 -1.3726 0.1604 -0.1855 1.3826 ans = 8 ans = -0.5146 2.2106 2.7200 -1.2136 1.0004 1.3089 0.7225 0.2746 -0.8798 0.2978 -0.8490 1.6744 1.1998 -0.0363 1.9105 -0.7747 -0.8707 -0.6823 0.6801 1.3194 -0.0685 0.5944 1.5078 -1.6821 0.0876 1.2150 -0.0747 0.0324 -1.1552 0.0966 -0.0624 -0.3874 -0.5356 0.6353 1.4090 -1.1014 ans = 6 ans = 0.5866 -1.0222 -0.2168 0.8582 1.4360 0.0699 2.0677 -0.4740 -0.8763 1.7827 0.1930 -1.2167 -0.3941 -0.5441 0.3719 -0.0609 0.7138 -1.0920 0.3622 -0.0459 -0.0221 0.2030 -0.7695 -0.8963 -0.1986 -0.2560 0.6666 0.4831 -1.2028 -0.9423 0.1656 1.2006 -1.1131 0.7704 -0.6906 -1.3143 ans = 5 ans = -0.5782 -0.3634 1.5381 -1.3173 -0.9493 0.8480 1.5921 -0.4069 0.7795 -0.3390 -0.1071 0.4201 -0.0184 0.2865 -0.1139 -0.1171 0.2288 0.5511 0.1787 0.7583 0.3994 1.0457 0.3291 -0.9150 0.3641 -0.6420 -0.2096 0.7761 0.4022 -0.7478 0.1165 0.7142 0.7029 -1.1195 0.0905 0.6810 ans = 4 ans = 0.1246 -0.3173 0.8068 0.6485 -0.8572 0.2275 0.3674 -0.0507 -0.9196 0.6161 -0.5821 -0.4291 -1.0142 -1.1614 -2.5438 1.5915 2.0356 0.4535 -0.2111 -0.3974 0.0376 0.3825 -1.9702 1.5318 -0.3890 0.9210 -0.0635 0.3248 1.8666 -0.0160 1.3908 -0.7204 -0.6772 -0.0713 0.0569 0.5929 ans = 3 ans = -0.1602 0.6891 0.4725 0.0277 -2.0510 -2.2440 -0.7497 1.8225 -0.4433 0.4090 0.9021 -1.6683 0.0659 0.3909 0.2043 0.9065 1.4630 0.3091 -0.3886 0.6715 -0.9742 -0.5468 0.2890 0.5625 -0.4558 0.4770 -0.1888 -0.6504 0.3281 1.3767 0.3983 0.5834 0.9360 0.8604 -0.9776 0.6755 ans = 10 ans = -0.4843 -0.4512 0.7544 0.7585 -0.4417 -0.0208 1.8537 -1.6935 -2.7067 -0.5077 0.9616 -1.7904 -1.6943 -1.0988 0.1208 -0.8100 1.8778 1.1654 1.1759 -0.7087 -1.2673 -0.1381 -0.0710 0.5343 0.2589 -0.5128 -0.3970 0.6737 0.8097 2.7024 -0.8933 0.2810 0.8117 -0.5428 -0.8782 1.1746 ans = 9 ans = 0.0254 -0.7993 1.5164 1.2921 -1.1013 1.8556 -0.6280 0.9374 -0.1962 0.1685 -0.5079 0.4333 -0.3962 -0.9977 0.6971 -1.0310 -1.1997 -2.1391 0.7179 1.0177 -0.8874 -0.6732 0.7295 1.4448 -1.1793 -1.3210 1.5292 0.2280 1.9337 1.0901 -0.0926 0.1798 -1.1740 0.3447 2.4578 0.4170[/code] I wonder if the code is correct, and does it retain the state of the global stream after the function call? Please help me, thank you very much

How extract (changeable variable) word & number using regular expression matlab

I have more than 10k text files look similar like this, all of them are similar in format but not in size, sometime is bigger or smaller.
[code][{u'language': u'english', u'area': 3825.8953168044045, u'class': u'machine printed', u'utf8_string': u'troia', u'image_id': 428035, u'box': [426.42422762784093, 225.33333055900806, 75.15151515151516, 50.909090909090864], u'legibility': u'legible', u'id': 1056659}, {u'language': u'na', u'area': 24201.285583103767, u'id': 1056660, u'image_id': 428035, u'box': [223.99998520359847, 249.57575480143228, 172.12121212121215, 140.6060606060606], u'legibility': u'illegible', u'class': u'machine printed'}] [/code] I want to extract two changeable variable in every text using regular expression.

The output should be like this
[code]box = [223.99998520359847, 249.57575480143228, 172.12121212121215, 140.6060606060606] box1 = .. sometime there is more than one [/code] & second output
[code]word = troia word1 = ... sometime there is more than one word [/code] My code 1: for the word extraction
[code]fid = fopen('text1.txt','r'); C = textscan(fid, '%s','Delimiter',''); fclose(fid); C = C{:}; Lia = ~cellfun(@isempty, strfind(C,'utf8_string')); output = [C{find(Lia)}]; expression = 'u''utf8_string'': u+' matchStr = regexp(output, expression,'match');[/code] My code 1 result give me only the
[code]utf8_string[/code] My code 2: for the box number extraction
[code]s = sprintf('text_.txt'); fid = fopen(s); tline = fgetl(fid); C = regexp(tline,'u''box'': +\[([0-9\. ,]+)\]','tokens'); C = cellfun(@(x) x{1},C,'UniformOutput',false)'; M = cell2mat(cellfun(@(x) x', cat(1,C2{:}),'UniformOutput',false));[/code] This code 2 is running but not with every text something i got this error
[code]Error using cat Dimensions of matrices being concatenated are not consistent[/code]

Retaining color when subsampling a triangulated surface: get indices from reducepatch?

I have a very densely tessellated surface which looks like this: White matter dense
[img]https://i.stack.imgur.com/gcNFn.png[/img]
This surface is too densely tessellated for me, so I subsample it to get a coarser surface. To do this, I used Matlab's reducepatch function. This works pretty well: [code]https://i.stack.imgur.com/U6sVm.png[/code] White matter subsampled

Unfortunately, the coloring is based on a variable called sulcal_depth, which is defined for every vertex of my tessellated surface. So I need to retain sulcal depth information only from the vertices which remain after subsampling. Essentially, I need reducepatch to give me not just the subsampled version of the surface, but also the indices of vertex points that it retained. If I know the preserved indices, I can just index my sulcal_depth variable to get the new depth map.

Currently, I'm doing this as follows (this is also how I colored the subsampled version above):
[code]function indices = compute_reduced_indices(before, after) %% Function to compute the indices of vertices preserved during an operation of % reducepatch. This allows you to use reducepatch to subsample a surface and % re-compute an original signal on the vertices for the new subsampled mesh indices = zeros(length(after), 1); for i = 1:length(after) dotprods = (before * after(i, :)') ./ sqrt(sum(before.^2, 2)); [~, indices(i)] = max(dotprods); end[/code] But as you might imagine, this is pretty slow, because of the for loop over vertices. I don't have enough memory to vectorize the loop and compute the full dot product matrix in one go.

Is there a smart way to get reducepatch to give me indices, or an alternative approach (with or without reducepatch) that's faster?

Linprog function in Matlab

I have a system X(k+1) = Ax(k) + Bu(k) and I have a cost function which needs to be minimised. I need to find the optimal u(k) that minimises x(k). How can this be done using 'linprog' function on Matlab? The linear constraints are in terms of u(k) and x(k) but I need to find just the optimal u(k).