logo
down
shadow

How to efficiently evaluate element in javascript array by using reduce function


How to efficiently evaluate element in javascript array by using reduce function

By : user3045034
Date : December 01 2020, 04:52 PM
With these it helps You can use a Set to store all the cities from the array and, since a set only has unique entries, the final size of the set will give you the number of distinct cities:
code :
const people = [
  { name: "Jessica", city: "New York"},
  { name: "Steve",   city: "Los Angels"},
  { name: "Peter",   city: "Boston"},
  { name: "Elaine",  city: "Montreal"},
  { name: "Chris",  city: "Montreal"},
  { name: "Mike",  city: "Boston"},
  { name: "George",  city: "Vancouver"},
];

let nbre_distinct_cities = new Set(people.map(({city}) => city)).size;
console.log('Total number of distinct cities: ', nbre_distinct_cities); 


Share : facebook icon twitter icon
jQuery/Javascript: How can I evaluate the validity of function arguments efficiently with a range of valid types?

jQuery/Javascript: How can I evaluate the validity of function arguments efficiently with a range of valid types?


By : user2968743
Date : March 29 2020, 07:55 AM
wish helps you It depends to what extent you want to do this. In idea would be to create a validation function which takes a argument -> rule mapping. E.g.:
code :
function foo(somestring, somenumber) {

    var rules = {
       'somestring': Validator.rules.isString,
       'somenumber': Validator.rules.inRange(5,10);
    };


} 
var Validator = {
    valid: function(args, rules) {
        for(var name in rules) {
            if(!rules[name](args[name])) {
                return false;
            }
        }
        return true;
    },
    rules: {
        isString: function(arg) {
            return (typeof arg === 'string');
        },
        inRange: function(x,y) {
            return function(arg) {
                return !isNaN(+arg) && x <= arg && arg <= y;
            }
        }
    }
}
function ensure(func, rules, context) {
    context = context || this;
    return function() {
        if(Validator.valid(arguments, rules)) {
            return func.apply(context, arguments);
        }
        return null; // or throw error, whatever you want
    }
}
var foo = function(somestring, somenumber) {
    // ...
};
var rules = {...};
foo = ensure(foo, rules);
Evaluate absolute value of array element in function

Evaluate absolute value of array element in function


By : Taral
Date : March 29 2020, 07:55 AM
I think the issue was by ths following , You are calling return from inside the inner loop. Therefore, your function returns just after it evaluates the first member of u.
Since you are using NumPy, you should take advantage of NumPy's ability to operate on the whole array at once, and also of NumPy's smart indexing.
code :
def softthreshold(u, LAMBDA):
    notzero = np.fabs(u) > LAMBDA # find the indeces of elements that need to be scaled
    rr = np.zeros_like(u) # an array the same size/type as u, already initialized to 0
    rr[notzero] = (np.fabs(u[notzero])-LAMBDA)*u[notzero]/np.fabs(u[notzero]) # scale each of the members that aren't zero
    return rr
Efficiently construct array with 2-element Array{Float64,1} returned by a function

Efficiently construct array with 2-element Array{Float64,1} returned by a function


By : Andrey
Date : March 29 2020, 07:55 AM
may help you . RecursiveArrayTools.jl has a VectorOfArray type which dispatches in the way you'd want:
code :
julia> using RecursiveArrayTools

julia> A = [rand(2) for i=1:3]
3-element Array{Array{Float64,1},1}:
 [0.957228, 0.104218]
 [0.293985, 0.83882]
 [0.788157, 0.454772]

julia> VectorOfArray(A)'
3×2 Array{Float64,2}:
 0.957228  0.104218
 0.293985  0.83882
 0.788157  0.454772
julia> @benchmark VectorOfArray(A)'
BenchmarkTools.Trial:
  memory estimate:  144 bytes
  allocs estimate:  2
  --------------
  minimum time:     100.658 ns (0.00% GC)
  median time:      111.740 ns (0.00% GC)
  mean time:        127.159 ns (3.29% GC)
  maximum time:     1.360 μs (82.71% GC)
  --------------
  samples:          10000
  evals/sample:     951
Efficiently evaluate a function of an array's values _and_ indices

Efficiently evaluate a function of an array's values _and_ indices


By : user3556372
Date : March 29 2020, 07:55 AM
will be helpful for those in need For a machine learning project I am doing, I need to transform a 2D array of floats to another array of the same shape where elements to the left and below are at least as large as the given element. , You can make use of two "cummulative maximum" calls:
code :
from np.mx import maximum as mx

mx.accumulate(mx.accumulate(A), axis=1)
>>> A
array([[1, 2, 1, 1],
       [1, 1, 6, 5],
       [3, 2, 4, 2]])
>>> mx.accumulate(mx.accumulate(A), axis=1)
array([[1, 2, 2, 2],
       [1, 2, 6, 6],
       [3, 3, 6, 6]])
>>> timeit(lambda: mx.accumulate(mx.accumulate(A), axis=1), number=100)
1.5123104000231251
How to efficiently evaluate a whole Python list of functions element-wise?

How to efficiently evaluate a whole Python list of functions element-wise?


By : shivam pal
Date : March 29 2020, 07:55 AM
To fix the issue you can do For arbitrary Python functions, a Python-level loop is unavoidable. One way is via a list comprehension:
code :
f_list = [f1,f2,f3]
values = np.array([1,2,3])
res = np.array([func(val) for func, val in zip(f_list, values)])
Related Posts Related Posts :
  • redux how to use state
  • All data in the db is lost when closing a express based node js server
  • How to convert javascript code for Angular
  • XPath select on child nodes
  • Idle event on mouse move - how to stop script permanently on mouse move
  • Why do I get logic is not defined in this code
  • When I enter a number in the input, the first function starts
  • ES6 imports and node_modules hell
  • How to get css selector of clicked-on element?
  • How to auto input MySQL data (input column 1 data to auto input column 2 data with same column) in php?
  • Appending to Datalist Via Javascript
  • Customizing Material-UI Components with Styled-Components
  • Populate elements with class name using Javascript
  • How to execute promises in batches (first resolving 10, then next 10 and so on)
  • Maximo JS automation script: "importPackage" is not defined
  • How to surround selected text inside textarea with <em> on key combination CTRL+i?
  • Your configured registry does not support audit requests ~ On npm audit
  • What's the Angular equivalent of Vue <slot/>?
  • Iconify icon not updating when "data-icon" set with setAttribute()
  • Javascript newbie stuck with XMLHttpRequest return data
  • How to add obj to to state in my example Redux React
  • Loading "grunt-karma.js" tasks...ERROR >> SyntaxError: Unexpected identifier
  • Why do I get log is not defined
  • get the multiple index of the same string
  • How can I iterate over an Array object by using For IN or FOR OF
  • Launch local executable from web browser
  • How to prepare array of json objects to d3 hierarchical tree structure
  • VueJS - event emitted - show HTML before other calculations
  • Export SASS/SCSS variables to Javascript without exporting them to CSS
  • How to attach an event handler only once continuously
  • How to make button open a link in new tab in JavaScript?
  • Find range from the javascript object
  • How can I use my jQuery code as JavaScript?
  • How to show 5 images in a 2 row slider with bxslider
  • How to convert stream into variables in typescript
  • Three.js custom shader error on Chrome GL_INVALID_OPERATION: Active draw buffers with missing fragment shader outputs
  • My JavaScript doesn't work. How can I solve this problem?
  • Why is this async function is running synchronously?
  • Get updated variable from within react hook before return
  • I want to show all image preview but whenever I upload a new one the old one is gone
  • Would I be able to give access to specific electron APIs safely?
  • Why several clicks fire for each instance of a Class?
  • cant grab value from div using attr()
  • Instantiate subclass without constructing
  • Outputing a created object in javascript to a server side JSON file
  • Transition the numeric labels in a bar chart
  • createBottomTabNavigator: hide just one tab from the tabBar
  • iife vs simple statement behavior with document.title
  • showDialogPopup Refresh Page after Click
  • Child component does not set the initial value passed from the parent: ReactJS
  • Nodejs javascript added to button not responding
  • Trying to define a promise.all
  • Python GEE to extract featurecollection timeseries from Landsat imageries
  • How to write negative binary number?
  • Unable to set property of individual object
  • Why Named Function Expression itself cannot assign Name to another Value?
  • How to reset scroll position on single page pagination
  • How to scroll to bottom of page, when a new message is sent - Socket.io
  • How to reconstruct audio blob from a base64 encoded String?
  • How to calculate numbers within an array of objects
  • shadow
    Privacy Policy - Terms - Contact Us © festivalmusicasacra.org