Tutorial by Examples: agg

Generating a new object in each step: var elements = new[] {1,2,3,4,5}; var commaSeparatedElements = elements.Aggregate( seed: "", func: (aggregate, element) => $"{aggregate}{element},"); Console.WriteLine(commaSeparatedElements); //1,2,3,4,5, Using th...

var letters = "letters".ToCharArray(); char letter = letters[1]; Console.WriteLine("Second Letter is {0}",letter); //in the above example we take the second character from the array //by calling letters[1] //NB: Array Indexing starts at 0; i.e. the first letter would be give...

It is possible to define an array with more than one dimension. Instead of being accessed by providing a single index, a multidimensional array is accessed by specifying an index for each dimension. The declaration of multidimensional array can be done by adding [] for each dimension to a regular a...

Using the Cars Table, we will calculate the total, max, min and average amount of money each costumer spent and haw many times (COUNT) she brought a car for repairing. Id CustomerId MechanicId Model Status Total Cost SELECT CustomerId, SUM(TotalCost) OVER(PARTITION BY Cust...

A function identified immediately before a template literal is used to interpret it, in what is called a tagged template literal. The tag function can return a string, but it can also return any other type of value. The first argument to the tag function, strings, is an Array of each constant piece...

Unlike the WHERE clause, HAVING can be used with aggregate functions. An aggregate function is a function where the values of multiple rows are grouped together as input on certain criteria to form a single value of more significant meaning or measurement (Wikipedia). Common aggregate function...

Payments Table CustomerPayment_typeAmountPeterCredit100PeterCredit300JohnCredit1000JohnDebit500 select customer, sum(case when payment_type = 'credit' then amount else 0 end) as credit, sum(case when payment_type = 'debit' then amount else 0 end) as debit from payments group by ...

You can use any element as an handle to drag another element around: <script> $(function() { $( "#draggable" ).draggable({ handle: ".handle" }); }); </script> <div id="draggable"> <span class="handle"&...

import pandas as pd import numpy as np df = pd.DataFrame({'Name':['Mary', 'Jon','Lucy', 'Jane', 'Sue', 'Mary', 'Lucy'], 'Age':[35, 37, 40, 29, 31, 26, 28], 'City':['Boston', 'Chicago', 'Los Angeles', 'Chicago', 'Boston', 'Boston', 'Chicago'], ...

Aggregate Applies an accumulator function over a sequence. int[] intList = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 }; int sum = intList.Aggregate((prevSum, current) => prevSum + current); // sum = 55 At the first step prevSum = 1 At the second prevSum = prevSum(at the first step) + 2 At the i-t...

Average The AVG() aggregate function will return the average of values selected. SELECT AVG(Salary) FROM Employees Aggregate functions can also be combined with the where clause. SELECT AVG(Salary) FROM Employees where DepartmentId = 1 Aggregate functions can also be combined with group by ...

The difference between size and count is: size counts NaN values, count does not. df = pd.DataFrame( {"Name":["Alice", "Bob", "Mallory", "Mallory", "Bob" , "Mallory"], "City":["Seattle", &q...

Who says you cannot throw multiple exceptions in one method. If you are not used to playing around with AggregateExceptions you may be tempted to create your own data-structure to represent many things going wrong. There are of course were another data-structure that is not an exception would be mor...

In [1]: import numpy as np In [2]: import pandas as pd In [3]: df = pd.DataFrame({'A': list('XYZXYZXYZX'), 'B': [1, 2, 1, 3, 1, 2, 3, 3, 1, 2], 'C': [12, 14, 11, 12, 13, 14, 16, 12, 10, 19]}) In [4]: df.groupby('A')['B'].agg({'mean': np.mean, 'standard deviatio...

Jagged arrays are arrays that instead of primitive types, contain arrays (or other collections). It's like an array of arrays - each array element contains another array. They are similar to multidimensional arrays, but have a slight difference - as multidimensional arrays are limited to a fixed nu...

The modules of a multi-module project are aggregated from a hierarchical structure. The root pom packing should look like: <packaging>pom</packaging> The following will be the directory structure of the project: |-- sample-app \ `-- pom.xml |-- sample-module-1 | `--...

-XXaggressive is a collection of configurations that make the JVM perform at a high speed and reach a stable state as soon as possible. To achieve this goal, the JVM uses more internal resources at startup; however, it requires less adaptive optimization once the goal is reached. We recommend that y...

Aggregation operations computes a single value from a collection of values. Aggregate Performs a custom aggregation operation on the values of a collection. Method Syntax // Aggregate var numbers = new int[] { 1, 2, 3, 4, 5 }; var product = numbers.Aggregate(1, (acc, n) => acc * n);...

Note the parenthesis to distinguish between a jagged array and a multidimensional array SubArrays can be of different length Dim jaggedArray()() As Integer = { ({1, 2, 3}), ({4, 5, 6}), ({7}) } ' jaggedArray(0) is {1, 2, 3} and so jaggedArray(0)(0) is 1 ' jaggedArray(1) is {4, 5, 6} and so jagge...

The List.fold_left and List.fold_right functions are higher-order functions that implement the outer logic of list aggregation. Aggregating a list, sometimes also referred to as reducing a list, means computing a value derived from the sequential inspection of all items in that list. The documenta...