how to convert pandas dataframe to binary file in python-CodePudding

import numpy as np
import pandas as pd
def get_values_for_frequency(freq):
    # sampling information
    Fs = 100# sample rate no of samppes per second
    T = 1/Fs # sampling period   %sample per second
    t = 1 # seconds of sampling
    N = Fs*t # total points in signal
    # signal information
    #freq = 100 # in hertz, 
    omega = 2*np.pi*freq # angular frequency for sine waves
    t_vec = np.arange(N)*T # time vector for plotting
    y = np.sin(omega*t_vec)
    return y
df = pd.DataFrame(columns =['1Hz','2Hz', '3Hz', '4Hz', '5Hz', '6Hz', '7Hz'])
df['1Hz']=pd.Series(get_values_for_frequency(1))
df['2Hz']=pd.Series(get_values_for_frequency(2))
df['3Hz']=pd.Series(get_values_for_frequency(3))
df['4Hz']=pd.Series(get_values_for_frequency(4))
df['5Hz']=pd.Series(get_values_for_frequency(5))
df['6Hz']=pd.Series(get_values_for_frequency(6))
df['7Hz']=pd.Series(get_values_for_frequency(7))
#df.to_csv('samplepersecond.csv')
ndary=df.to_records(index=False)

This is the code to generate a sine wave .Here I generated a sine wave with 7 columns(from 1 Hz to 7 Hz) and with 100 rows. Then I created a pandas Dataframe to store all these values. Now , the requirement is to convert this Dataframe into binary file with datatype of int16. So each value in a dataframe should be converted into 16 bit signed integer and then to convert into binary file

CodePudding user response：

You can convert your data frame values to int16 by using the astype function.

import numpy as np

df = df.astype(np.int16)

Then you can save your data frame in HDF5 format by using to_hdf.

df.to_hdf('tmp.hdf','df', mode='w')