Combine Two Arrays

let a = [1,2,3,4,5]let b = [6,7,8,9,10]let combine = a.map((e, i) => [e, b[i]]);console.log(combine);

How do I concatenate or merge arrays in Swift?

You can concatenate the arrays with +, building a new array

let c = a + b
print(c) // [1.0, 2.0, 3.0, 4.0, 5.0, 6.0]

or append one array to the other with += (or append):

a += b

// Or:
a.append(contentsOf: b)  // Swift 3
a.appendContentsOf(b)    // Swift 2
a.extend(b)              // Swift 1.2

print(a) // [1.0, 2.0, 3.0, 4.0, 5.0, 6.0]

How to combine two arrays for a specific index without concatenation?

I think that you're looking for numpy.insert

array1 = np.arange(95,320,4)
array2 = np.arange(0,360,2)

for i, value in enumerate(array1):
  index = i+48+i*2
  array2 = np.insert(array2, index, array1[i])

combine two arrays in Javascript/react

initialNav and AdminNav are objects, not arrays. You want this instead:

const NewNav = { items: [...initialNav.items, ...AdminNav.items] };

How to conditionally combine two numpy arrays of the same shape

We could use NumPy built-in np.maximum, made exactly for that purpose -

np.maximum(array1, array2)

Another way would be to use the NumPy ufunc np.max on a 2D stacked array and max-reduce along the first axis (axis=0) -

np.max([array1,array2],axis=0)

Timings on 1 million datasets -

In [271]: array1 = np.random.randint(0,9,(1000000))

In [272]: array2 = np.random.randint(0,9,(1000000))

In [274]: %timeit np.maximum(array1, array2)
1000 loops, best of 3: 1.25 ms per loop

In [275]: %timeit np.max([array1, array2],axis=0)
100 loops, best of 3: 3.31 ms per loop

# @Eric Duminil's soln1
In [276]: %timeit np.where( array1 > array2, array1, array2)
100 loops, best of 3: 5.15 ms per loop

# @Eric Duminil's soln2
In [277]: magic = lambda x,y : np.where(x > y , x, y)

In [278]: %timeit magic(array1, array2)
100 loops, best of 3: 5.13 ms per loop

Extending to other supporting ufuncs

Similarly, there's np.minimum for finding element-wise minimum values between two arrays of same or broadcastable shapes. So, to find element-wise minimum between array1 and array2, we would have :

np.minimum(array1, array2)

For a complete list of ufuncs that support this feature, please refer to the docs and look for the keyword : element-wise. Grep-ing for those, I got the following ufuncs :

add, subtract, multiply, divide, logaddexp, logaddexp2, true_divide,
floor_divide, power, remainder, mod, fmod, divmod, heaviside, gcd,
lcm, arctan2, hypot, bitwise_and, bitwise_or, bitwise_xor, left_shift,
right_shift, greater, greater_equal, less, less_equal, not_equal,
equal, logical_and, logical_or, logical_xor, maximum, minimum, fmax,
fmin, copysign, nextafter, ldexp, fmod

Javascript how to join two arrays having same property value?

I think you can use array#reduce to do something like this perhaps:

var array1 = [        {'label':"label1",'position':0},        {'label':"label3",'position':2},        {'label':"label2",'position':1},    ];
var array2 = [        {'label':"label1",'value':"TEXT"},        {'label':"label2",'value':"SELECT"}     ];
var array3 = array2.reduce((arr, e) => {  arr.push(Object.assign({}, e, array1.find(a => a.label == e.label)))  return arr;}, [])

console.log(array3);

import numpy as np

first = np.array([[650001.88, 300442.2,   18.73,  0.575,  
                   650002.094, 300441.668, 18.775],
                  [650001.96, 300443.4,   18.7,   0.65,   
                   650002.571, 300443.182, 18.745],
                  [650002.95, 300442.54,  18.82,  0.473,  
                   650003.056, 300442.085, 18.745]])

second = np.array([[1],
                   [2],
                   [3]])

np.concatenate((first, second), axis=1)

const 
    original = [{ id: 4, quantity: 4 }, { id: 2, quantity: 2 }, { id: 76, quantity: 2 }],
    selected = [{ id: 2, quantity: 1 }, { id: 100, quantity: 7 }],
    merged = [...original, ...selected].reduce((r, { id, quantity }) => {
        const item = r.find(q => q.id === id);
        if (item) item.quantity += quantity;
        else r.push({ id, quantity });
        return r;
    }, []);

console.log(merged);

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