multiplying

This question already has an answer here: How do I operate on a DataFrame with a Series for every column 2 answers What is the best way to multiply all the columns of a Pandas DataFrame by a column vector stored in a Series ? I used to do this in Matlab with repmat() , which doesn't exist in Pandas. I can use np.tile() , but it looks ugly to convert the data structure back and forth each time. Thanks. Wes McKinney What's wrong with result = dataframe.mul(series, axis=0) ? https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.mul.html#pandas.DataFrame.mul This can be

hh=[[82.5], [168.5]] N=1./5 ll=N*hh What I'm doing wrong? I received error : "can't multiply sequence by non-int of type 'float'" I try to add float(), but this is not solve my problem; I need to multiply each element in array... thanks to all **Ok thanks for idea for number * array, but how to multiply array*array, I tried same as number*array, but have problems: EDIT 2:** hh=[[82.5], [168.5]] N=zip(*hh) ll = [[x*N for x in y] for y in hh] ??? When you multiply a sequence by X in Python, it doesn't multiply each member of the sequence - what it does is to repeat the sequence X times. That's

I have an embedded 16 bit CPU. On this machine ints are 16 bit wide and it supports longs that are 32 bits wide. I need to do some multiplications that will need to be stored in 64 bits (e.g. multiply a 32 bit number by a 16 bit number). How can I do that with the given constraints? I do not have a math library to do this. Just another metaprogrammer A suggestion in C. Note that this code probably will be easier to implement with inline assembler as carry detection in C doesn't seem that easy // Change the typedefs to what your compiler expects typedef unsigned __int16 uint16 ; typedef

I'm a designer looking into learning Swift and I'm a beginner. I have no experience whatsoever. I'm trying to create a tip calculator using basic code in Xcode's playground. Here is what I have so far. var billBeforeTax = 100 var taxPercentage = 0.12 var tax = billBeforeTax * taxPercentage I get the error: Binary operator '*' cannot be applied to operands of type 'Int' and 'Double' Does this mean I can't multiply doubles? Am I missing any of the basic concepts of variables and doubles here? You can only multiple two of the same data type. var billBeforeTax = 100 // Interpreted as an Integer

i've the following code in Javascript: var m1 = 2232.00; var percent = (10/100); var total = percent*m1; alert(total); The problem is that the variable "total" gives me "223.20000000000002" and it should be "223.2", what should i do to get the correct value? .toFixed() is best solution.It will keep only two digits after dot. Exp 1: var value = 3.666; value.toFixed(2); //Output : 3.67 Exp 2: var value = 3.0000; value.toFixed(2); //Output : 3.00 Niet the Dark Absol You can't get the exact value. This is the fundamental problem with floating-point numbers. You can force a fixed number of decimal

I'm trying to measure some activity in C (Matrix multiplying) and noticed that I should do something like this: clock_t start = clock(); sleep(3); clock_t end = clock(); double elapsed_time = (end - start)/(double)CLOCKS_PER_SEC; printf("Elapsed time: %.2f.\n", elapsed_time); The output is: Elapsed time: 0.00. Why is this happening? clock estimates the CPU time used by your program; that's the time the CPU has been busy executing instructions belonging to your program. sleep doesn't perform any work, so it takes no noticeable CPU time (even if it takes wallclock time). If you want to measure

I want to multiply 2 cells for each row and put the value of that in the last column called Total. Can this be done by a normal query? Example: Pieces | Price | Total 6 | 4 | null // should be 24 2 | 10 | null // should be 10 Prescott Use this: SELECT Pieces, Price, Pieces * Price as 'Total' FROM myTable You can do it with: UPDATE mytable SET Total = Pieces * Price; I'm assuming this should work. This will actually put it in the column in your database UPDATE yourTable yt SET yt.Total = (yt.Pieces * yt.Price) If you want to retrieve the 2 values from the database and put your multiplication in

I need to multiply an array by another array, just like vectors in math. E.g.: A = [1,2,3,4] B = [2,3,4,5] C = A*B = [2,6,12,20] I can't even figure out the code, i've tried doing so element by element but this seems to messy of a solution for me, any ideas? (I'm a complete beginner with swift) "Zipping" the two arrays gives a sequence of tuples (a_i, b_i) which can then be multiplied element-wise: let A = [1,2,3,4] let B = [2,3,4,5] let C = zip(A, B).map { $0 * $1 } print(C) // [2, 6, 12, 20] (If the arrays have different length then zip silently ignores the extra elements of the longer array