I'm having a bit of trouble iterating through a few if statements more than eight times. The code seems to work fine for the first several comparisons, performs the arithmetic and return/saves the output row 'export_data'. However, after that, it only returns the else condition and response. The variables beings assessed have 1500 rows each. I've added the code below and two photos showing the outputs. Any insight will be very much appreciated.
function [export_data] = WS_Zones(Forecast_WS, Observed_WS)
if (Forecast_WS > Observed_WS)
WS_Zone_1 = Observed_WS.*1.24;
WS_Zone_2 = Observed_WS.*1.28;
elseif (Forecast_WS < Observed_WS)
WS_Zone_1 = Observed_WS.*0.76;
WS_Zone_2 = Observed_WS.*0.72;
else
WS_Zone_1 = Observed_WS;
WS_Zone_2 = Observed_WS;
end
export_data=[Forecast_WS Observed_WS WS_Zone_1 WS_Zone_2];
filename = 'testdata.xlsx';
sheet = 1;
xlRange = 'A1';
xlswrite(filename,export_data,sheet,xlRange)
end
Expected Output
Wrong Output
This statement:
if [1 2 3] > [1 1 1]
disp('hello');
end
will never print "hello" even though 2 and 3 are both greater than 1. This is because the if statement needs to evaluate to either scalar true or false. If a vector is used, than only the first element is used to determine if the statement is true or not (comparisons between other elements are ignored). You can use any and all if you want to apply conditions on all elements.
If Forecast_WS and Observed_WS aren't scalars then you need to wrap your if statement in a for loop, e.g.:
WS_Zone_1 = Observed_WS;
WS_Zone_2 = Observed_WS;
for i = 1:numel(Forecast_WS)
if Forecast_WS(i) > Observed_WS(i)
WS_Zone_1(i) = Observed_WS(i).*1.24;
WS_Zone_2(i) = Observed_WS(i).*1.28;
elseif Forecast_WS(i) < Observed_WS(i)
WS_Zone_1(i) = Observed_WS(i).*0.76;
WS_Zone_2(i) = Observed_WS(i).*0.72;
end
end
or vectorize it using logical indexing:
WS_Zone_1 = Observed_WS;
WS_Zone_2 = Observed_WS;
idx = (Forecast_WS > Observed_WS);
WS_Zone_1(idx) = Observed_WS(idx).*1.24;
WS_Zone_2(idx) = Observed_WS(idx).*1.28;
idx = (Forecast_WS < Observed_WS);
WS_Zone_1(idx) = Observed_WS(idx).*0.76;
WS_Zone_2(idx) = Observed_WS(idx).*0.72;
Related
How can I collapse the values of "deep" struct fields into arrays by just indexing?
In the example below, I can only do it for the "top-most" level, and for "deeper" levels I get the error:
"Expected one output from a curly brace or dot indexing expression, but there were XXX results."
The only workaround I found so far is to unfold the operation into several steps, but the deeper the structure the uglier this gets...
clc; clear variables;
% Dummy data
my_struc.points(1).fieldA = 100;
my_struc.points(2).fieldA = 200;
my_struc.points(3).fieldA = 300;
my_struc.points(1).fieldB.subfieldM = 10;
my_struc.points(2).fieldB.subfieldM = 20;
my_struc.points(3).fieldB.subfieldM = 30;
my_struc.points(1).fieldC.subfieldN.subsubfieldZ = 1;
my_struc.points(2).fieldC.subfieldN.subsubfieldZ = 2;
my_struc.points(3).fieldC.subfieldN.subsubfieldZ = 3;
my_struc.info = 'Note my_struc has other fields besides "points"';
% Get all fieldA values by just indexing (this works):
all_fieldA_values = [my_struc.points(:).fieldA]
% Get all subfieldM values by just indexing (doesn't work):
% all_subfieldM_values = [my_struc.points(:).fieldB.subfieldM]
% Ugly workaround:
temp_array_of_structs = [my_struc.points(:).fieldB];
all_subfieldM_values = [temp_array_of_structs.subfieldM]
% Get all subsubfieldZ values by just indexing (doesn't work):
% all_subsubfieldZ_values = [my_struc.points(:).fieldC.subfieldN.subsubfieldZ]
% Ugly workaround:
temp_array_of_structs1 = [my_struc.points(:).fieldC];
temp_array_of_structs2 = [temp_array_of_structs1.subfieldN];
all_subsubfieldZ_values = [temp_array_of_structs2.subsubfieldZ]
Output:
all_fieldA_values =
100 200 300
all_subfieldM_values =
10 20 30
all_subsubfieldZ_values =
1 2 3
Thanks for any help!
You can use arrayfun to have acces to each individual 'point', and then acces its data. This will return an array with the same dimensions as my_struc.points:
all_subfieldM_values = arrayfun(#(in) in.fieldB.subfieldM, my_struc.points)
all_subsubfieldZ_values = arrayfun(#(in) in.fieldC.subfieldN.subsubfieldZ, my_struc.points)
Not optimal, but at least it's one line.
In one of my GUIs I load DICOM images. Sometimes they are just a volume and another dimension and when I load them in Matlab everything ends up where I want it.
handles.inf = dicominfo([filepath filename]);
handles.dat = dicomread(handles.inf);
size(handles.dat)
ans = 128 128 128 512
For an 128 by 128 by 128 volume at 512 timepoints for example (actually the third dimension would not even be 128, the third dimension is stacks, of which I don't know what it is). However sometimes There are more dimensions in the dicom, but the reader just puts all of them in the fourth dimension.
handles.inf = dicominfo([filepath filename]);
handles.dat = dicomread(handles.inf);
size(handles.dat)
ans = 128 128 1 4082
For a single 128 by 128 slice with 512 timepoints, two echoes and magnitude, phase, real and imaginary data for example.
It is then very hard to unscramble them. Manually I can do this for every DICOM I load but when in a GUI I would want to have a general approach that just creates a dimension in the array for each dimension in the dicom.
This is especially important not just for data-analysis, but also to transform the coordinates from image space to patient space. My own approach was to look at the header, but there's no guarantee that certain entries will work, and the order in which they are applied I can't find. The header entries I found so far:
inf.Rows;%inf.width;%inf.MRAcquisitionFrequencyEncodingSteps;%inf.MRAcquisitionPhaseEncodingStepsInPlane
inf.Columns;% inf.height; % inf.NumberOfKSpaceTrajectories;
inf.MRSeriesNrOfSlices
inf.MRSeriesNrOfEchoes
inf.MRSeriesNrOfDynamicScans
inf.MRSeriesNrOfPhases
inf.MRSeriesReconstructionNumber % not sure about this one
inf.MRSeriesNrOfDiffBValues
inf.MRSeriesNrOfDiffGradOrients
inf.MRSeriesNrOfLabelTypes
reshapeddat = reshape(dat, [all dimension sizes from header here]);
I'm not sure how to check if I've got all variables and what the right order for the reshape. Anybody knows of a sure-fire way to get all dimension sizes from the DICOM header and the order in which they are stacked?
Ok so I now manually go by all possible dimensions. When a stack also contains reconstructed data which has less dimensions than the rest, remove those first.
This is how I check the dimensions:
info = dicominfo(filename);
datorig = dicomread(filename);
%dimension sizes per frame
nrX = double(info.Rows); %similar nX;% info.width;% info.MRAcquisitionFrequencyEncodingSteps;% info.MRAcquisitionPhaseEncodingStepsInPlane
nrY = double(info.Columns); %similar nY;% info.height;% info.NumberOfKSpaceTrajectories;
%dimensions between frames
nrEcho = double(info.MRSeriesNrOfEchoes);
nrDyn = double(info.MRSeriesNrOfDynamicScans);
nrPhase = double(info.MRSeriesNrOfPhases);
nrSlice = double(info.MRSeriesNrOfSlices); %no per frame struct entry, calculate from offset.
%nr of frames
nrFrame = double(info.NumberOfFrames);
nrSeq = 1; % nSeq not sure how to interpret this, wheres the per frame struct entry?
nrBval = double(info.MRSeriesNrOfDiffBValues); % nB
nrGrad = double(info.MRSeriesNrOfDiffGradOrients); % info.MRSeriesNrOfPhaseContrastDirctns;%similar nGrad?
nrASL = 1; % info.MRSeriesNrOfLabelTypes;%per frame struct entry?
imtype = cell(1, nrFrame);
for ii = 1:nrFrame
%imtype(ii) = eval(sprintf('info.PerFrameFunctionalGroupsSequence.Item_%d.PrivatePerFrameSq.Item_1.MRImageTypeMR', ii));
imtype{ii} = num2str(eval(sprintf('info.PerFrameFunctionalGroupsSequence.Item_%d.PrivatePerFrameSq.Item_1.MRImageTypeMR', ii)));
end
imType = unique(imtype, 'stable');
nrType = length(imType);
This is how I reformat the dimensions:
%% count length of same dimension positions from start
if nrEcho > 1
for ii = 1:nrFrame
imecno(ii) = eval(sprintf('inf.PerFrameFunctionalGroupsSequence.Item_%d.PrivatePerFrameSq.Item_1.EchoNumber', ii));
end
lenEcho = find(imecno ~= imecno(1), 1, 'first') - 1;
else
lenEcho = nrFrame;
end
if nrDyn > 1
for ii = 1:nrFrame
imdynno(ii) = eval(sprintf('inf.PerFrameFunctionalGroupsSequence.Item_%d.PrivatePerFrameSq.Item_1.TemporalPositionIdentifier', ii));
end
lenDyn = find(imdynno ~= imdynno(1), 1, 'first') - 1;
else
lenDyn = nrFrame;
end
if nrPhase > 1
for ii = 1:nrFrame
imphno(ii) = eval(sprintf('inf.PerFrameFunctionalGroupsSequence.Item_%d.PrivatePerFrameSq.Item_1.MRImagePhaseNumber', ii));
end
lenPhase = find(imphno~=imphno(1), 1, 'first') - 1;
else
lenPhase = nrFrame;
end
if nrType > 1
q = 1;
imtyno(1, 1) = q;
for ii = 2:nrFrame
if imtype{:, ii-1} ~= imtype{:, (ii)}
q = q+1;
end
imtyno(1, ii) = q;
%for jj = 1:nrType
%if imtype{:,ii} == imType{:,jj}
% imtyno(1, ii) = jj;
%end
%end
end
if q ~= nrType
nrType = q;
end
lenType = find(imtyno ~= imtyno(1), 1, 'first') - 1;
else
lenType = nrFrame;
end
% slices are not numbered per frame, so get this indirectly from location
% currently not sure if working for all angulations
for ii = 1:nrFrame
imslice(:,ii) = -eval(['inf.PerFrameFunctionalGroupsSequence.Item_',sprintf('%d', ii),'.PlanePositionSequence.Item_1.ImagePositionPatient']);
end
% stdsl = std(imslice,[],2); --> Assumption
% dirsl = max(find(stdsl == max(stdsl)));
imslices = unique(imslice', 'rows')';
if nrSlice > 1
for ii = 1:nrFrame
for jj = 1:nrSlice
if imslice(:,ii) == imslices(:,nrSlice - (jj-1)); %dirsl or :?
imslno(1, ii) = jj;
end
end
end
lenSlice = find(imslno~=imslno(1), 1, 'first')-1;
else
lenSlice = nrFrame;
end
if nrBval > 1
for ii = 1:nrFrame
imbno(ii) = eval(sprintf('inf.PerFrameFunctionalGroupsSequence.Item_%d.PrivatePerFrameSq.Item_1.MRImageDiffBValueNumber', ii));
end
lenBval = find(imbno~=imbno(1), 1, 'first') - 1;
else
lenBval = nrFrame;
end
if nrGrad > 1
for ii = 1:nrFrame
imgradno(ii) = eval(sprintf('inf.PerFrameFunctionalGroupsSequence.Item_%d.PrivatePerFrameSq.Item_1.MRImageGradientOrientationNumber', ii));
end
lenGrad = find(imgradno~=imgradno(1), 1, 'first')-1;
else
lenGrad = inf.NumberOfFrames;
end
lenSeq = nrFrame; % dont know how to get this information per frame, in my case always one
lenASL = nrFrame; % dont know how to get this information per frame, in my case always one
%this would have been the goal format
goaldim = [nrSlice nrEcho nrDyn nrPhase nrType nrSeq nrBval nrGrad nrASL]; % what we want
goallen = [lenSlice lenEcho lenDyn lenPhase lenType lenSeq lenBval lenGrad lenASL]; % what they are
[~, permIX] = sort(goallen);
dicomdim = zeros(1, 9);
for ii = 1:9
dicomdim(1, ii) = goaldim(permIX(ii));
end
dicomdim = [nrX nrY dicomdim];
%for any possible zero dimensions from header use a 1 instead
dicomdim(find(dicomdim == 0)) = 1;
newdat = reshape(dat, dicomdim);
newdim = size(newdat);
newnonzero = length(newdim(3:end));
goalnonzero = permIX(1:newnonzero);
[dummyy, goalIX] = sort(goalnonzero);
goalIX = [1 2 goalIX+2];
newdat = permute(newdat, goalIX);
newdat = reshape(newdat, [nrX nrY goaldim]);
When Ive used this as a function for a longer period and debugged it a bit I might post in on the file exchange of mathworks.
I need to iterate Newton-Raphson.The problem is:
For mmm=1:
1) If m=1 take c1=c1b and c2=1-c1 and do the loop for u1,2(i) and p1,2(i)
2)If m=2 take c1=c1+dc and c2=1-c1, and this time do the loop with new c1 and c2 for u1,2(i) and p1,2(i)
3) If m=3 take c1=(c1*st(1)-(c1-dc)*st(2))/(st(1)-st(2)) and do the loop for new c1 and c2.
Then increase the iteration number: mmm=2 ;
mmm keeps count of the number of N-R iterations. The first iteration has mmm=1, the second mmm=2, etc. (This particular run only do 2 iterations).
sumint are inside of the integrals. 'c1, c2 are the camber effects, u1 u2 are the velocities, p1 p2 are pressures.
Relevant part of the code:
ii=101;
ub = cell(2, 1);
ini_cond = [0,0];
for i = 1:2;
ub{i} = zeros(1,ii);
ub{i}(:, ii) = ini_cond(i) * rand(1, 1);
end
for i=1:ii;
x=i*dx;
fikness = fik*sin(pi.*x);
ub{1}(i) = (c1b-H1D*(x-0.5)+AD/2.*(x-0.5).^2)./(H1-0.5*fikness-A*(x-0.5));
ub{2}(i) = (c2b+H1D*(x-0.5)-AD/2.*(x-0.5).^2)./(1.-H1+0.5*fikness+A*(x-0.5));
end
mmm = 1;
c1 = c1b;
m = 1;
c2=1-c1;
u = cell(2, 1);
ini_cond = [0,0];
for i = 1:2;
u{i} = zeros(1,ii);
u{i}(:, ii) = ini_cond(i) * rand(1, 1);
end
for i=1:ii;
x=(i-1)*dx;
fikness = fik*sin(pi.*x);
u{1}(i) = (c1-H1D*(x-0.5)+AD/2.*(x-0.5).^2)./(H1-0.5*fikness-A*(x-0.5));
u{2}(i)= (c2+H1D*(x-0.5)-AD/2.*(x-0.5).^2)./(1.-H1+0.5*fikness+A*(x-0.5));
end
p = cell(2, 1);
q = cell(2, 1);
for i = 1:2;
p{i} = zeros(1,100);
q{i} = zeros(1,100);
end
p{1}(1) = 0.5*(1.-u{1}(1).^2);
q{1}(1) = 0;
p{2}(1) = 0.5*(1.-u{2}(1).^2);
q{2}(1) = 0;
for i = 2:ii;
q{1}(i) = q{1}(i-1)-dx*(u{1}(i-1)-ub{1}(i-1))./dt;
p{1}(i) = 0.5*(1.-u{1}(i).^2)+q{1}(i);
q{2}(i) = q{2}(i-1)-dx*(u{2}(i-1)-ub{2}(i-1))./dt;
p{2}(i) = 0.5*(1.-u{2}(i).^2)+q{2}(i);
end
st = zeros(2, 1);
st(1,:) = p{1}(100)-p{2}(100);
m = m+1;
if m==3;
c1=(c1*st(1)-(c1-dc)*st(2))/(st(1)-st(2));
c2=1-c1;
end
sumint = cell(2, 1);
for i = 1:2
sumint{i} = zeros(1,length(x));
end
sumint{1}(1) = 0.5*(p{2}(1)-p{1}(1));
sumint{2}(1) = 0.5*(p{2}(1)-p{1}(1)).*(-1/2);
for i = 2:100;
x=(i-1)*dx;
sumint{1}(i) = sumint{1}(i-1)+(p{2}(i)-p{1}(i));
sumint{2}(i) = sumint{2}(i-1)+(p{2}(i)-p{1}(i)).*(x-1/2);
end
The error is: ??? Attempted to access u.%cell(2); index out of bounds because numel(u.%cell)=1.
Error in ==> grab3_SmithWilson at 75 p{1}(i)=0.5*(1.-u{1}(i).^2)+q{1}(i);
You need to show us what you want to see. When I run the code you posted now, I find that first ub is printed as you have written, then each cell of ub is overwritten on each loop iteration. What I mean is that you are not putting values into the arrays that are stored in the cells, you are putting values in to the cells themselves. Are you sure that's what you want?
If you want to store the calculation in the elements of the arrays that are stored in the cells, the following will work:
for i=1:ii;
x=(i-1)*dx;
fikness=fik*sin(pi.*x);
ub{1}(i)=(c1b-H1D*(x-0.5)+AD/2*(x-0.5)^2)/(H1-0.5*fikness-A*(x-0.5));
ub{2}(i)=(c2b+H1D*(x-0.5)-AD/2*(x-0.5)^2)/(1-H1+0.5*fikness+A*(x-0.5));
end
>> ub
ub =
[1x101 double]
[1x101 double]
This is why I suggested reading about accessing parts of cells. Really though, this is just a guess until you tell us what you want from your script.
I am using an API to get real data times of trains and am trying to get the closest train time to a user entered time and then display that train time, and the next 4 granted the trains are running. I am reading in the information and the code goes through what its supposed to do but when I look at the array its a bunch of [] brackets in 7 cells instead of the calculated numbers. Any suggestions? Code is below with the API
TEST VALUES:
requestStationSelected = 'University%20City' and requestEndStation = 'Roslyn'
%this is the API link for the live data from Septa this will get 30
%results and see which time is closer to the user entered time
requestInfoSeptaLive = ['http://www3.septa.org/hackathon/NextToArrive/' requestStationSelected '/' requestEndStation '/30'];
%Again tries to get the information and if there is a failure it will give
%a probable cause and terminate the program
try
getInfoSeptaLive = urlread(requestInfoSeptaLive);
catch
if getInfoSeptaLive ~= '[]'
disp...
('Either the arrival/depart stations dont quite match up or theres a server error. Try again.');
return;
else
disp('Unable to fetch the information from Septa, please try again')
return;
end
end
%parses the information returned from the Live API
dataReturnedFromLiveAPI = parse_json(getInfoSeptaLive);
dataReturnedFromLiveAPI = dataReturnedFromLiveAPI{1};
%gets the size of the API in case there are no trains running
sizeOfDataNoTrains = size(dataReturnedFromLiveAPI, 1);
sizeOfData = size(dataReturnedFromLiveAPI, 2);
counter = 0;
for i = 1:sizeOfData
scanForClosestTime = dataReturnedFromLiveAPI{1,i}.orig_departure_time;
trainTimeGivenH = sscanf(scanForClosestTime, '%i');
findColonTrain = strfind(scanForClosestTime, ':');
trainTimeGivenMStr = scanForClosestTime(findColonTrain+1:4);
trainTimeGivenM = int32(str2num(trainTimeGivenMStr));
trainDepartTimeM = (trainTimeGivenH(1,1) * 60) + (trainTimeGivenM);
differenceBetweenTimes = trainDepartTimeM - userEnteredMins;
if trainDepartTimeM < userEnteredMins
differenceBetweenTimes = userEnteredMins - trainDepartTimeM;
end
stopAtEndOfData = sizeOfData;
goodTimeFrame = 60;
closestTime = cell(1, stopAtEndOfData);
storeTheDifference = cell(1, stopAtEndOfData);
if(differenceBetweenTimes < 60)
if (counter < 5)
closestTime{i} = scanForClosestTime;
storeTheDifference{i} = differenceBetweenTimes;
counter = counter + 1;
end
end
end
You assign your cell arrays inside the for loop:
for i = 1:sizeOfData
...
closestTime = cell(1, stopAtEndOfData);
storeTheDifference = cell(1, stopAtEndOfData);
...
end
This means that you turn both of them into an array of {[],[],[],[],[]...} on every iteration of the loop - so unless the last iteration has a valid "closest Time" in it, your cell array will be all empty arrays - and if it does, all but the last element will still be [].
To fix this, move the two lines to before the start of the for loop.
The second problem seems to be the indexing of the arrays where you store the results. If you only want five results, I am assuming you want to store them in elements 1 - 5 of your array, and not in "just any" locations. I would change the code to
if (counter < 5)
counter = counter + 1;
closestTime{counter} = scanForClosestTime;
storeTheDifference{counter} = differenceBetweenTimes;
end
But maybe I misinterpreted how you want to handle that?
Unrelated to your question, you might want to take a look at the line
trainTimeGivenMStr = scanForClosestTime(findColonTrain+1:4);
It is quite possible that this is not what you intended to do - looking at an example of the response, I found the string "orig_departure_time":"11:57PM". I expect that findColonTrain == 3, so that the above line becomes
trainTimeGivenMStr = scanForClosestTime(4:4);
just a single character. Perhaps you meant
trainTimeGivenMStr = scanForClosestTime(findColonTrain+(1:4));
which would turn into
trainTimeGivenMStr = scanForClosestTime(4:7);
so that
trainTimeGivenMStr = '57PM';
I hope these three things help you get it all working!
EDIT: had a chance to run your code this morning - discovered a number of other problems. I include below an annotated "working" code: the biggest problem was most likely that you were not handling AM/PM in your code. Note that I used a different json parser - this changed a couple of lines very slightly. I'm sure you can put it back together to work the way you want. This returned valid data in all cells.
dataReturnedFromLiveAPI = loadjson(getInfoSeptaLive);
% next line not needed - loadjson returns struct array, not cell array
%dataReturnedFromLiveAPI = dataReturnedFromLiveAPI{1};
%gets the size of the API in case there are no trains running
sizeOfDataNoTrains = size(dataReturnedFromLiveAPI, 1);
sizeOfData = size(dataReturnedFromLiveAPI, 2);
counter = 0;
stopAtEndOfData = sizeOfData;
closestTime = cell(1, stopAtEndOfData);
storeTheDifference = cell(1, stopAtEndOfData);
userEnteredMins = 12*60+30; % looking for a train around 12:30 pm
for ii = 1:sizeOfData
scanForClosestTime = dataReturnedFromLiveAPI(ii).orig_departure_time;
trainTimeGivenH = sscanf(scanForClosestTime, '%i');
% since we'll be considering AM/PM, have to set 12 = 0:
if (trainTimeGivenH == 12), trainTimeGivenH = 0; end
findColonTrain = strfind(scanForClosestTime, ':');
% change next line to get minutes plus AM/PM:
trainTimeGivenMStr = scanForClosestTime(findColonTrain+(1:4));
% look at just minutes:
trainTimeGivenM = int32(str2num(trainTimeGivenMStr(1:2)));
% adjust for AM/PM:
if(trainTimeGivenMStr(3:4)=='PM'), trainTimeGivenH = trainTimeGivenH+12; end;
% compute time in minutes:
trainDepartTimeM = (trainTimeGivenH * 60) + (trainTimeGivenM);
differenceBetweenTimes = trainDepartTimeM - userEnteredMins;
if trainDepartTimeM < userEnteredMins
differenceBetweenTimes = userEnteredMins - trainDepartTimeM;
end
% added a couple of lines to see what is happening:
fprintf(1, 'train %d: depart %s - in minutes this is %d vs user entered %d\n', ...
ii, scanForClosestTime, trainDepartTimeM, userEnteredMins);
goodTimeFrame = 60;
if(differenceBetweenTimes < 600)
if (counter < 10)
counter = counter + 1;
closestTime{counter} = scanForClosestTime;
storeTheDifference{counter} = differenceBetweenTimes;
end
end
end
I have an array:
step1 = [0,0;
0,1;
1,1;
2,3;
3,4;
3,5;
3,6;
3,7;
4,7;
5,7;
6,7;
6,6;
6,5;
6,4;
6,3;
6,2;
5,1];
I want to step through this array and create new arrays for the row and column that increment by 0.1 from one row to another. This is what I did:
z=1;
u=length(step1);
step_b4X = zeros(u,1);
step_b4Y = zeros(u,1);
while z <= length(step1)
step_b4X = step_presentX;
step_presentX(z,1) = step1(z,1);
step_b4Y = step_presentX;
step_presentY(z,1) = step1(z,2);
pathX = step_b4X:0.1:step_presentX;
pathY = step_b4Y:0.1:step_presentY;
z = z+1;
end
I get zeros.
I want pathX = 0:0.1:0....pathY = 0:0.1:1
next pathX = 0:0.1:1....pathY = 1:0.1:1... and so on
If you do
start:increment:end
where start == end, you'll get a scalar equal to start (which is logical).
If you want pathX and pathY to have the same length at each iteration, you'll have to do this:
z = 1;
while z <= length(step1)
currentX = step(z,1); nextX = step(z+1,1);
currentY = step(z,2); nextY = step(z+1,2);
pathX = currentX : 0.1 : nextX;
pathY = currentY : 0.1 : nextY;
if numel(pathX) == 1
pathX = repmat(pathX, numel(pathY),1); end
if numel(pathY) == 1
pathY = repmat(pathY, numel(pathX),1); end
z = z+1;
end
Now you'll have the right arrays at each iteration, that you'll use directly or save in a cell-array for later. If you want everything in one big array, add this to the end of the loop:
pathX_final = [pathX_final; pathX];
pathY_final = [pathY_final; pathY];
and initialize them as empty before the loop, of course.
Alternatively (much cleaner and possibly a bit faster), ditch the whole loop and use interp1:
x = step1(:,1);
y = step1(:,2);
xx = interp1(1:numel(x), x, 1:0.1:numel(x));
yy = interp1(1:numel(y), y, 1:0.1:numel(y));