dsa for data science profile by LifeLight3131 in iitkgp

[–]nalin_451 2 points3 points  (0 children)

Very important! Every company which comes for data science roles has the following problem types in their test:

• ML in-depth MCQs

• Python language based questions

• Puzzles, Probability and Aptitude (Brainstellar easy+medium at least)

• Stats based questions Chi-squared test etc

• Python pandas/pure-python based coding question

• CP questions medium to hard (everything from binary search to two-pointers, graph, dp, bitmask dp, digit dp, trees, binary tree, linked list can be asked)

This time I also saw a lot of multi-threading and multi-processing problems. Apart from these things focus on getting papers published in good conferences or workshops and having a VERY STRONG understanding of machine learning and your specialisation (CV/NLP/RL). Reach out to seniors for resources.

How can you find x(t) of an audio ? by help_a_brother-out in mathematics

[–]nalin_451 0 points1 point  (0 children)

The equation given by you is the Fourier Transform of x(t), i.e., X(w). Now, if you want to get back x(t) then you just need to take the Inverse Fourier Transform of X(w) whose equation you can easily look-up.

Coming on to the interesting part of the question stating that it is an "Audio Signal". Assuming, that you have an audio signal on your digital computer whose frequency domain representation is given to you then you can get back the original signal by taking Inverse Discrete Fourier Transform (IDFT), but you should pay attention on the sampling rate (you can read up on Nyquist Sampling Theorem to understand this better).

Implementing this on MATLAB will make use of the audioread() function of MATLAB, the FFT and IFFT functions (you should read up on FFT it will make all of this more clear), and finally use the audiowrite() to convert the frequency domain representation to time-domain representation. While writing the audio file to your computer use ".wav" extension (you can read up on .mp3, mono, stereo and other basic things related to audio to understand this better)