Raising a number to a power in Java

^ in java does not mean to raise to a power. It means XOR. You can use java’s Math.pow() And you might want to consider using double instead of int—that is: Note that 199/100 evaluates to 1.

math in java – what does ” %” do?

% is the Modulus operator. For Java Modulus: For example: 10 % 3 is equal to 1. To visually see this – You can think of it as “How much would I have to subtract to the value on the left in order to make it evenly divisible by the right hand value?” And yes, actually it’s … Read more

Drop data frame columns by name

You can use a simple list of names : Or, alternatively, you can make a list of those to keep and refer to them by name : EDIT : For those still not acquainted with the drop argument of the indexing function, if you want to keep one column as a data frame, you do: drop=TRUE (or not … Read more

Categories R

DataFrame constructor not properly called

The pd.DataFrame constructor does not accept a dictionary view as data. You can convert to list instead. Here’s a minimal example: The docs do suggest this: data : numpy ndarray (structured or homogeneous), dict, or DataFrame Equivalently, you can use pd.DataFrame.from_dict, which accepts a dictionary directly:

Convert pandas dataframe to NumPy array

df.to_numpy() is better than df.values, here’s why.* It’s time to deprecate your usage of values and as_matrix(). pandas v0.24.0 introduced two new methods for obtaining NumPy arrays from pandas objects: to_numpy(), which is defined on Index, Series, and DataFrame objects, and array, which is defined on Index and Series objects only. If you visit the v0.24 docs for .values, you will see a big red warning that says: Warning: We recommend … Read more

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