Here we use numpy which is a general purpose array processing package in python.
Plotting mat file in python.
You can get the file used in this post here.
Text files are structured as a sequence of lines where each line includes a sequence of characters.
Scipy is a really popular python library used for scientific computing and quite naturally they have a method which lets you read in mat files.
Python build in functions read readline and readlines in general a text file txt is the most common file we will deal with.
The result is a numpy array.
Here are examples of how to read two variables lat and lon from a mat file called test mat.
The scipy s module loadmat and savemat can easily read and write the data stored in the python variable into the mat file respectively.
Here is the documentation of the plot method for you to further explore.
Note that pandas dataframe plot is a convenient wrapper around matplotlib to create simple plots.
Matlab up to 7 1 mat files created with matlab up to version 7 1 can be read using the mio module part of scipy io reading structures and arrays of structures is supported elements are accessed with the same syntax as in matlab.
Output of above program looks like this.
These are more powerful and faster.
Struct its lat element can.
To get corresponding y axis values we simply use predefined np sin method on the numpy array.
Plotting curves from file data as explained earlier matplotlib only handles plotting.
If you want to plot data stored in a file you will have to use python code to selection from matplotlib plotting cookbook book.
To set the x axis values we use np arange method in which first two arguments are for range and third one for step wise increment.
The recommended way of plotting data from a file is therefore to use dedicated functions such as numpy loadtxt or pandas read csv to read the data.
By the way in this spectrum mat file there are two columns e g x axis frequency and y axis scale and 401 rows.
Coming from the academia the annotations for the dataset was in the mat format.
Could anyone please let me know that why i can t plot this spectrum mat file kindly if someone show me the procedure for plotting mat files.
Then plot the obtained data using matplotlib.
The numbers provided to the plot method are interpreted as the y values to create the plot.
Let s assume we need to import in python the following text file sample txt.
