I want to calculate the running sum in a given column(without using loops, of course). The caveat is that I have this other column that specifies when to reset the running sum to the value present ...

I'd like to find a vectorized way to calculate the cumulative sums of a vector, but with upper and lower limits. In my case, the input only contains 1's and -1's. You can use this assumption in yo...

Say I have an array like this >>> a = np.arange(1,8).reshape((1,-1)) >>> a array([[1, 2, 3, 4, 5, 6, 7]]) and I want to create, for each of the items in a, a "cumsum of the nex...

Suppose data looks like group1 group2 num A sg 1 A sh 2 A sg 4 B at 3 B al 7 a <- cumsum(data[,"num"]) # 1 3 7 10 17 I need something accumulated by groups. In reality,I have multiple ...

Suppose I have 2 input vectors x and reset of the same size x = [1 2 3 4 5 6] reset = [0 0 0 1 0 0] and an output y which is the cumulative sum of the elements in x. Whenever the value of reset...

Is there a function in numpy or scipy (or some other library) that generalizes the idea of cumsum and cumprod to arbitrary function. For example, consider the (theoretical) function cumf( func, ar...

I have a very large dataset that looks simplified like this: row. member_id entry_id comment_count timestamp 1 1 a 4 2008-06-09 12:41:00 2 1 b 1 2008-07-14 18:41:00 3 1 c 3 2008-07-17 15:40:00 4 2...

I have a pandas DataFrame with timedeltas as a cumulative sum of those deltas in a separate column expressed in milliseconds. An example is provided below: Transaction_ID Time TimeDelta CumSum[ms]...

I'm trying to calculate the inventory of stocks from a table in monthly buckets in Pandas. This is the table: Goods | Incoming | Date -------+------------+----------- 'a' | 10 | 2014-01-10 'a' | 2...

I'm very new to python and numpy, so sorry if I misuse some terminology. I have converted a raster to a 2D numpy array in the hopes of doing calculations on it quickly and efficiently. I need to...

If I have this I get an error sum(vector) == cumsum(vector)(length(vector)) >> Error: ()-indexing must appear last in an index expression. I know I can just do: Vec1 = cumsum(mat); sum(m...

I want to compute the integral image. for example a=array([(1,2,3),(4,5,6)]) b = a.cumsum(axis=0) This will generate another array b.Can I execute the cumsum in-place. If not . Are there any oth...

I have a set of UNIX timestamps and URIs and I'm trying to plot the cumulative count of requests for each URI. I managed to do that for one URI at a time using a dummy column: x.df$count <- app...

I feel like this is a fairly easy question, but for the life of me I can't seem to find the answer. I have a fairly standard dataframe, and what I am trying to do is sum the a column of values unti...

I am looking for a succinct way to go from: a = numpy.array([1,4,1,numpy.nan,2,numpy.nan]) to: b = numpy.array([1,5,6,numpy.nan,8,numpy.nan]) The best I can do currently is: b = numpy.inse...

I have an array of element probabilities, let's say [0.1, 0.2, 0.5, 0.2]. The array sums up to 1.0. Using plain Python or numpy, I want to draw elements proportional to their probability: the firs...