I found myself needing to compute the “integer cube root”, meaning the cube root of an integer, rounded down to the nearest integer. In Python, we could use the NumPy floating-point cbrt() function: Though this works most of the time, it fails at certain input x, with the result being one less tha…
Tag: floating-point
How many times can you divide 24**36 by 2 until it becomes imprecise?
How many times can you divide 24**36 by 2 until it becomes imprecise? I had this question on one of my quizzes in a python course, and I’m curious as to what the correct answer is. (It’s already submitted so no cheating here) I wrote this small bit of code in python to calculate how many times you…
How to disable python rounding?
I’m looking for a way to disable this: print(0+1e-20) returns 1e-20, but print(1+1e-20) returns 1.0 I want it to return something like 1+1e-20. I need it because of this problem: returns f1 is the original function, f2 is f1 shifted by 1 to the left and f3 is f2 moved back by 1 to the right. By this log…
Exctract a value from a Json file(python)
Hi i’m not an expert and this problem kept me stuck for such a long time I hope that someone here can help me i would like to exctract the value “interestExpense” from the following json file: In this case the result should be -130000000 as a string but i m trying to find a way to create an …
Python large numbers (float and integer)
I am trying to understand the following calculation results. Out[1], Out[2] and Out[3] seem to be related to the limit on precision of floats, and Out[4] may be due to the fact that there is no limit on digits of int. Correct? I wonder if someone can explain them in more detail. Answer To understand why this …
Trying to find averages from a .txt but I keep getting ValueError: could not convert string to float: ”
I’m using the txt file: https://drive.google.com/file/d/1-VrWf7aqiqvnshVQ964zYsqaqRkcUoL1/view?usp=sharin I’m running the script: And I ALWAYS get the error: ValueError: could not convert string to float: ” I’m pretty new-ish to Python and I’m really not sure what I’m doing…
How is python’s float.__eq__ implemented in the language?
I know that the best way to compare two floats for equality is usually to use math.isclose(float_a, float_b). But I was curious to know how python does it if you simply do float_a == float_b. I suppose it’s implemented in C, but what is the logic behind it ? Answer Here is the source code for float obje…
Multiple data types in a python list
I have a list for birth data each record has 3 columns for [DOB, weight, height] as such: I need to change the data types of this as they are all strings in the list I want the first item in the record to be datetime and then the rest to be floats. I have: I get an attribute error:
Why do I lose numerical precision when extracting element from list in python?
I have a pandas dataframe that looks like this: I am trying to extract the 1st element from the Series of lists using this code: and I get this result: Why do I lose precision and what can I do to keep it? Answer By default, pandas displays floating-point values with 6 digits of precision. You can control the…
It doesn’t append as floating Python | Problem #18
I’m writing this code for the problem #18 in Codeabbey. I need to calculate the square root of an array of numbers [150, 0, 5, 1 10, 3] I have to divide this array in three arrays (x,n) [[150, 0], [5, 1], [10 3]] where x: is the number I want to calculate the square root of and n: is