Iterate over array and make calculation on elements
for loop in array
iterate through array java
for loop iterate through array python
I have an array that I want to sum specific elements while iterating through it. I struggle to find a way to do this with loop. The array shape is (25,25)
array [ 92843, 86851, 91950, 98232, 83329, 94591, 88962, 97020, 107113, 98452, 103242, 106442, 123032, 119063, 112971, 114715, 108654, 114856, 109872, 124583, 120518, 112815, 120780, 127831, 147174], [132633, 124073, 131357, 140331, 119041, 135131, 127089, 138601, 153019, 140647, 147489, 152061, 175761, 170090, 161388, 163879, 155221, 164080, 156960, 177976, 172169, 161165, 172544, 182617, 210249], [159159, 148887, 157629, 168397, 142849, 162157, 152507, 166321, 183623, 168776, 176986, 182473, 210913, 204108, 193665, 196655, 186265, 196896, 188352, 213571, 206602, 193398, 207052, 219140, 252298]
I want to print out results like below for each iteration
print(array+array) # 159159 + 148887 = 308046 print(array+array+array) #132633 + 124073 + 131357 = 388063 print(array+array+array+array) # 92843 + 86851 + 91950 + 98232 = 369876
Presenting each element as
array[i][j], as you can see in each iteration i - 1, and the "length" of j increased one.
Is there anyway I can use loop to do this task ? Thanks!
for i, sub in enumerate(reversed(array)): print(sum(sub[:i]))
For example, if
array = [[ 1, 2, 3, 4, 5], [ 6, 7, 8, 9, 10], [11, 12, 13, 14, 15], [16, 17, 18, 19, 20], [21, 22, 23, 24, 25]]
the output would be
0 # last row, no elements summed 16 # 16 = 16 23 # 11 + 12 = 23 21 # 6 + 7 + 8 = 21 10 # 1 + 2 + 3 + 4 = 10
You may simply want the
np.tril, followed by a
np.sum(_, axis=0). This will give the sum of each row of the lower triangle of the matrix. Easily altered to give the upper triangle, if that's what you need.
NumPy Array Iterating, Iterate Through an Array with a For Loop Hints Hint 1 Remember the structure of a for for-in loop and it seems that is better method to iterate through arrays and objects. A bit late to the game but it's better to take arr.length out of the loop so for After the code has calculated the total for this loop, it refers back to the i++ NumPy package contains an iterator object numpy.nditer. It is an efficient multidimensional iterator object using which it is possible to iterate over an array. Each element of an array is visited using Python’s standard Iterator interface. Let us create a 3X4 array using arange () function and iterate over it using nditer.
In : arr = np.arange(1,17).reshape(4,4) In : arr Out: array([[ 1, 2, 3, 4], [ 5, 6, 7, 8], [ 9, 10, 11, 12], [13, 14, 15, 16]]) In : for i in range(3,-1,-1): ...: c = arr[i,:4-i] ...: print(c.sum(), c) ...: 13  19 [ 9 10] 18 [5 6 7] 10 [1 2 3 4]
Node.js, To do that, we can use a loop to iterate over each element, repeating the to make sure that the counter variable i is less than the length of the steps array. Using the iterator variable as the index number is the fastest way to iterate the elements of an array: Dim items As Variantitems = Array(0, 1, 2, 3)Dim index As IntegerFor index = LBound(items) To UBound(items) 'assumes value can be implicitly converted to a String: Debug.Print items(index) Next.
Iteration over lists | AP CSP (article), to do element-wise array calculations. Method 2 uses array syntax, where looping over array elements happens implicitly (this syntax is also found in Fortran As you would in any other programming language, simply nest two for loops to iterate over the 2D array by index. If there's going to be a variable number of rows/columns, you can parse the return values of the GetArrayBounds() function to set the bounds of your iterations.
- The 3rd and the 2nd shared the same
i. Do you mean
23,22,21? And why do you have difficulty looping through the index?
- @knh190 yes you are right, I've edited the question
- If you are using
arrayis vague. Also try use the
arr[23,0]style of indexing.
- Thank you, but I received an error on the second line
TypeError: 'numpy.int64' object is not callable
- @Osca I can't reproduce that. Are you sure you typed in the code correctly?
- Yes, I copy paste the code. Even for the example array you made, I received the same error. Im using python3
- Thank you, but I want to print each layer's sum of the triangle, not just the sum of whole upper triangle
axisshould be outside of
- @Osca that is what this returns. I have edited to make that more clear.