Removing variables from a numpy array

Question

I have a code that creates this plot , but I don’t know how to remove the first data from “channel 1” - the red line, and the last data from “channel 3” - the blue line, these vertical lines. There are 266,336 entries in both channels, can you help? The red vertical line is the first record, and the blue is the last.

import iodata as io
import matplotlib.pyplot as plt
import numpy as np
import time

testInstance = io.InputConverter()
start = time.time()
conversionError = io.ConversionError()
#f = testInstance.convert(r"S:\Python\", 1", conversionError)
f = testInstance.convert(r"/Users/Hugo/20160401", "201604010000", 
conversionError)
end = time.time()
print("time elapsed " + str(end - start))

if(conversionError.conversionSucces):
    print("Conversion succesful")
if(conversionError.conversionSucces == False):
    print("Conversion failed: " + conversionError.conversionErrorLog)
print "Done!"

# Create a new subplot for two canals 1 & 3
a = np.amin(f.f)
filename = 'C:/Users/Hugo/20160401/201604010000.dat'
d = open(filename,'rb')
t = u"\u00b0"
headersize = 64
header = d.read(headersize)
ax1 = plt.subplot(211)
ax1.set_title(header[:16] + ', ' +                          # station name
     'Canals: '+header[32:33]+' and '+header[34:35]+ ', '   # canals
     +'Temp'+header[38:43]+t+'C'                            # temperature
    +', '+'Time:'+header[26:32]+', '+'Date'+' '+header[16:26])      # date

plt.ylabel('Pico Tesle [pT]')
plt.xlabel('Time [ms]')
plt.plot(f.f[0,], label='Canal 1', color='r', linewidth=0.75, linestyle="-")
plt.plot(f.f[1,], label='Canal 3', color='b', linewidth=0.75, linestyle="-")
plt.legend(loc='upper right', frameon=False)
plt.grid()
# Create a new subplot for FFT
plt.subplot(212)
plt.title('Fast Fourier Transform')
plt.ylabel('Power [a.u.]')
plt.xlabel('Frequency Hz')
FFTdata = np.sqrt(f.f[0,]*f.f[0,]+f.f[1,]*f.f[1,])**1
samples = FFTdata.size
duration = 300 # in seconds
Fs = float(samples)/duration # sampling frequency (sample/sec)
delta_t = 1.0/Fs
t = np.arange(0, samples, 1)*delta_t
FFTdata_freq = np.abs(np.fft.rfft(FFTdata))**2
freq = np.fft.rfftfreq(samples, d=delta_t)

# Printing data
plt.semilogy(freq, FFTdata_freq)
plt.grid()
#plt.savefig('S:/Hugo/'+"201604010000"+'.png', bbox_inches = 
'tight')
plt.show()

Content f.f:

>>> print f.f[0,]
[ -59.57011259 -74.20675537 -90.53224156 ..., -1676.9703173 -1676.9703173 -1676.9703173 ]

>>> print f.f[1,] 
[ 1.48413511e+00 4.96417605e+00 8.39303992e+00 ..., -1.67697032e+03 -1.67697032e+03 -1.67697032e+03] 

Iodata Code:

import struct
import numpy as np

class ConversionError:
    def __init__(self):
        self.conversionSucces = True
        self.conversionErrorLog = "Correct"

    def reportFailure(self, errorlog):
        self.conversionSucces = False
        self.conversionErrorLog = errorlog

class DataStruct:
    def __init__(self,f,initTime,headerString):
        self.f = f
        self.initTime = initTime
        self.headerString = headerString

class InputConverter:
    def __init__(self):
        self.midAdc = 65536/2
        self.convFactor = 19.54

    def convert(self,filePath,fileName,conversionLog):
        try:
            d_file = open(filePath + "/" + fileName + ".dat", mode='rb')
         except IOError as e:
            conversionLog.reportFailure(e.strerror)

        file = d_file.read()
        datalen = len(file)
        headerString = file[:43]
        initime, = struct.unpack('>H', file[48:50])
        expectedMatrixWidth = (datalen - 72)/4
        outputMatrix = np.zeros((2, expectedMatrixWidth))
        index = 0;
        print "Processing..."
        for i in range(64, datalen-8, 4):
            e1, e2 = struct.unpack('>HH',file[i:i+4])
            outputMatrix[0, index] = (e1 - self.midAdc)/self.convFactor
            outputMatrix[1, index] = (e2 - self.midAdc)/self.convFactor
            index += 1


        return DataStruct(outputMatrix,initime,headerString)

Answer 1

You can try using array slicing:

plt.plot(f.f[0,][1:], label='Canal 1', color='r', linewidth=0.75, linestyle="-")
plt.plot(f.f[1,][:-1], label='Canal 3', color='b', linewidth=0.75, linestyle="-")

Edit:

- , / , , @Dascienz . - , 50 :

plt.plot(f.f[0,][50:-50], label='Canal 1', color='r', linewidth=0.75, linestyle="-")
plt.plot(f.f[1,][50:-50], label='Canal 3', color='b', linewidth=0.75, linestyle="-")

Answer 2

, , , ...

---

1 3 . .

f.f[0,] ( 1, ) f.f[1,] ( 3, ): : -1676.97003.... (.. ) .

f.f[0,] ( 1, ): -60, -75 -90. , , 500 , -500. 2, , 50000, , 0.

, , , , / ( , ).