How do I combined all peak to become one spectral line?

2 次查看（过去 30 天）
Mohamad Khairul Ikhwan Zulkarnain
评论： Guillaume 2018-9-14
Hi guys, from the code I have I managed to produce the graph:
%get list of element, prompt user to select one, and get content of element file
filelist = dir('*.txt');
[~, elementlist] = arrayfun(@(f) fileparts(f.name), filelist, 'UniformOutput', false);
[elementindex, ok] = listdlg('ListString', elementlist, 'PromptString', 'Select an element', 'SelectionMode', 'single');
if ~ok, return; end %terminate if user click cancel
elementdata = importdata(filelist(elementindex).name);
assert(isnumeric(elementdata), 'Element does not have data'); %abort if the file does not contain a matrix
%build wavelength array
step = 0.02;
ss = 100;
steparray = -step*ss : step : step*ss;
new_wavelength = (elementdata(:, 1) + steparray); %no loop needed. Requires R2016b or latter
%get row selection
[selectedrow, ok] = listdlg('ListString', compose('%f', elementdata(:, 1)), 'PromptString', 'Select a wavelength', 'SelectionMode', 'multiple');
if ~ok, return; end %terminate if user click cancel
%build Peak vector for selected row
Delta_lambda = 0.2;
int_fact = elementdata(selectedrow, 2);
num = new_wavelength(selectedrow,ss+1)-new_wavelength(selectedrow,:);
denom = Delta_lambda/2;
Peak = (int_fact.*(1./(1+(num/denom).^2)));
%combined peak vector for selected row
plot(new_wavelength(selectedrow, :).', Peak.')
How do I combined all the peak that I chose to become as the graph below bcs I have try by using sum(peaks) but i doesnt work so im not sure how should I do it. One of the expert(Mathworks society) told me to resample each row to the same wavelength before i can sum it but im not sure how should i do it.
I have attached the element file as well. Thanks in advanced.
  3 个评论
显示 1更早的评论
Mohamad Khairul Ikhwan Zulkarnain
Mohamad Khairul Ikhwan Zulkarnain 2018-9-14
I got more than one peak at the same time bcs when i select the number of row for wavelength, i select more than one row which eventually will create more than one peak at a time. I dont think my peak share the same x-vector since each peak has its own row but as you see in the first picture, there are some part of the peak is overlapping. Cant we just sum it up? If not, what should I do to sum it up? Can you show it to me?

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

jonas
jonas 2018-9-14
编辑：jonas 2018-9-14
They key is to resample the curves along a common x-vector. You can do this by interp1. Just add these new lines of code:
% ... old code
Peak = (int_fact.*(1./(1+(num/denom).^2)));
% ...New code begins here
x=new_wavelength(selectedrow,:);
y=Peak;
% Remove rows with NaNs
x(isnan(y(:,1)),:)=[];
y(isnan(y(:,1)),:)=[];
% Number of peaks
np=size(y,1);
% New xvec
xh=min(x(:)):1e-3:max(x(:)); %new x vector
% Preallocate new peak vector
yh=nan(size(x,1),size(xh,2));
%Interpolate one peak at a time
for i=1:np
yh(i,:)=interp1(x(i,:),y(i,:),xh);
end
% Sum column-wise, exclude nans
ysum=nansum(yh,1);
% Plot
plot(xh,ysum)
First three wavelengths of Ferum:
  5 个评论
显示 3更早的评论

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Data Preprocessing 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by