how do i know which filter should i use?

Hi guys, I have been working on a smartphone sensor and I have the data. it consists of time acceleration in x y z-direction. so i tried to plot the time history of all three in one graph and guess what, it comes up EMPTY. can anybody clear this issue for me? secondly, when I run FFT for the data it shows a lot of peaks(it should be showing a few peaks right?) I know there is noise in the signal but then I don't know which filter to use. how am I suppose t know which kind of filter is suitable for which condition. and how am I suppose to remove the peaks now.. I

 have attached the data file (the data i used is till row 3767). i used the following code,,

%%Import data from text file.
% Script for importing data from the following text file:
%
%    F:\Masters BUW\MASTER ARBEIT\Sensor Simulation\Data\SM-G950F_samsung_dreamltexx.csv
%
% To extend the code to different selected data or a different text file,
% generate a function instead of a script.

% Auto-generated by MATLAB on 2018/10/19 00:51:50

%%Initialize variables.
filename = 'F:\Masters BUW\MASTER ARBEIT\Sensor Simulation\Data\SM-G950F_samsung_dreamltexx.csv';
delimiter = ' ';
startRow = 23;
endRow = 3767;

%%Format for each line of text:
%   column1: double (%f)
%  column2: double (%f)
%   column3: double (%f)
%  column4: double (%f)
% For more information, see the TEXTSCAN documentation.
formatSpec = '%f%f%f%f%*s%*s%[^\n\r]';

%%Open the text file.
fileID = fopen(filename,'r');

%%Read columns of data according to the format.
% This call is based on the structure of the file used to generate this
% code. If an error occurs for a different file, try regenerating the code
% from the Import Tool.
dataArray = textscan(fileID, formatSpec, endRow-startRow+1, 'Delimiter', delimiter, 'MultipleDelimsAsOne', true, 'TextType', 'string', 'EmptyValue', NaN, 'HeaderLines', startRow-1, 'ReturnOnError', false, 'EndOfLine', '\r\n');

%%Close the text file.
fclose(fileID);

%%Post processing for unimportable data.
% No unimportable data rules were applied during the import, so no post
% processing code is included. To generate code which works for
% unimportable data, select unimportable cells in a file and regenerate the
% script.

%%Allocate imported array to column variable names
tim = dataArray{:, 1};
x = dataArray{:, 2};
y = dataArray{:, 3};
z = dataArray{:, 4};

%%Clear temporary variables
clearvars filename delimiter startRow endRow formatSpec fileID dataArray ans;
%%mydata
t=tim-3.103056357614000e+03;
accx=detrend(x, 'constant');
accy=detrend(y, 'constant');
accz=detrend(z, 'constant');

X= [accx, accy, accz];

% 
 for i = 1:1:3 
 subplot(3,1,i)
  plot(t,X(i))

   end

Fs= 50;
T= 1/Fs;
L=3745;
time= (1:L-1)*T;

accxx= detrend(accx);

NFFT = 2^nextpow2(L); % Next power of 2 from length of y
Y = fft(accxx,NFFT,1);
f = Fs/2*linspace(0,1,NFFT/2);

% Plot single-sided amplitude spectrum.
figure
plot(f,abs(Y(1:NFFT/2))) 
title('Single-Sided Amplitude Spectrum of y(t)')
xlabel('Frequency (Hz)')
ylabel('|Y(f)|')

[Sheraz Khan]

sorry for the mess. i am new in matlab and thank you in advance

[Rik]

Today I formatted your code, next time, use the {}Code button. See here for a GIF showing how to do it.

[Star Strider]

If you have broadband noise (as it appears you do), a frequency-selective filter will not produce the results you want.

I would use the Wavelet Toolbox (link) functions instead.