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Maximum number of elements in a 2D array

I need to make an 2d array, but c# won't let me and says that it is too big, any ideas how to make it work?
int[,] arrayName = new int[37153,18366];

The max theoretical size of an int array is 2147483647 i.e. int[] array = new int[2147483647] but the probleming you're having here is that the computer runs of out memory.
Read this for explanation and tips on how to solve this:
OutOfMemoryException on declaration of Large Array

If you are not using the complete range of the array (which is in your case 2,7GB of RAM), you could use a Dictionary.
https://msdn.microsoft.com/de-de/library/xfhwa508(v=vs.110).aspx
Alternative: Create a [][] Array. In this case you must initialize each row.
But you can access each cell easy with arrayName[row][col].
int[][] arrayName = new int[37153][];
for(int i=0; i<arrayName.Length; i++)
arrayName[i] = new int[18366];

Converting <T>[][] to <T>[] by extracting 1 element from the inner array

Is there a potential 1 liner that allows me to create a new 1 dimensional array from a certain index of the inner array of the 2D?
Example take the first element of each inner array:
double[][] array2D = new double[10][] // with inner arrays say double[5]
double[] array1D = new double[10];
for (int i=0; i<array2D.Length; i++)
{
array1D[i] = array2D[i][0];
}

I'd just use LINQ. That won't "avoid loops" in terms of execution, but it'll avoid a loop in your source code:
// 1dArray isn't a valid identifier...
var singleArray = jaggedArray.Select(x => x[0]).ToArray();
Note that this relies on it being a jagged array (an array of arrays). It will not do what you expect for true multi-dimensional (rectangular) arrays.
Or slightly more efficiently:
var singleArray = Array.ConvertAll(jaggedArray, x => x[0]);
That's more efficient because it knows the output size to start with, and builds the array directly - but it's a bit less idiomatic than using LINQ these days (which is more generally applicable to all sequences, not just arrays).

How to pass part of a two-dimensional array as parameter to a function?

I've got a two-dimensional array like this:
double[,] results = new double[100,100];
I'd like to pass every one dimensional part of the array to a function as a paremeter.
for (int i = 0; i < 100; i++){
cool_function (results[???], 10);
}
How do I do this in C#?

source
Jagged arrays are arrays of arrays. The elements of a jagged array are other arrays.
Declaring Jagged Arrays
Declaration of a jagged array involves two brackets. For example, the following code snippet declares a jagged array that has three items of an array.
int[][] intJaggedArray = new int[3][];
The following code snippet declares a jagged array that has two items of an array.
string[][] stringJaggedArray = new string[2][];
Initializing Jagged Arrays
Before a jagged array can be used, its items must be initialized. The following code snippet initializes a jagged array; the first item with an array of integers that has two integers, second item with an array of integers that has 4 integers, and a third item with an array of integers that has 6 integers.
// Initializing jagged arrays
intJaggedArray[0] = new int[2];
intJaggedArray[1] = new int[4];
intJaggedArray[2] = new int[6];
We can also initialize a jagged array's items by providing the values of the array's items. The following code snippet initializes item an array's items directly during the declaration.
// Initializing jagged arrays
intJaggedArray[0] = new int[2]{2, 12};
intJaggedArray[1] = new int[4]{4, 14, 24, 34};
intJaggedArray[2] = new int[6] {6, 16, 26, 36, 46, 56 };

You can't do it without copying the corresponding part of the array.
Otherwise, you can use a double[][]. To initialize:
double[][] results = new double[100][];
for(int i = 0; i < 100; i++)
results[i] = new double[100];

You could do this by using a jagged array Type[][] instead of Type[,]. In this case you can just pass array[index]. Otherwise you will have to either pass the two-dimensional array together with the index of the subarray of interest and perform the indexing in the called method or create a copy of the subarray of interest.

If you mean for an array myarray[x][y] that you want to call a function for x arrays of size y then all you need is the following code:
int i;
for (i = 0; i < 100; i++)
{
cool_function(array[i], 10);
}

how to inset a new array to my jagged array

hello i will much apreciate any help.
ok let's see, first i have declare a jagged array like this and the next code
int n=1, m=3,p=0;
int[][] jag_array =new[n];
now my jagged array will have 1 array inside, next y have to fill the array like this:
car=2;
do
{
jag_array[p]= new double[car];
for (int t = 0; t < carac; t++)
{
jag_array[p][t] = variableX;
}
p=p+1
}
while(p==0)
now my jagged array looks like this(also insert some data for this example):
jag_array[0][0]=4
jag_array[0][1]=2
now my question how can i insert a new array whit out losing my previos data if i declare
jag_array[p+1]= new double[car];
i will lose the data from the previos one, i will like to look something likes this:
jag_array[0][0]=4
jag_array[0][1]=2
jag_array[1][0]=5
jag_array[1][1]=6
the reason i did not declare from the begining 2 array is beacuse i dont know how many i am going to use it could be just 1 or 20 and every time i have to create a new array whit out losing the previous data that has been already fill, thaks all for the attention,

The size of an array, once created, is by definition invariable. If you need a variable number of elements, use a List<T> - in your case, probably a List<int[]>.
The only alternative solution would be to created a new array with the new size (and assign that to your jag_array variable) and copy all the previous elements from your old array into the new array. That is unnecessarily complicated code when you can just use List<T>, but if you cannot use List<T> for any reason, here is an example:
// increase the length of jag_array by one
var old_jag_array = jag_array; // store a reference to the smaller array
jag_array = new int[old_jag_array.Length + 1][]; // create the new, larger array
for (int i = 0; i < old_jag_array.Length; i++) {
jag_array[i] = old_jag_array[i]; // copy the existing elements into the new array
}
jag_array[jag_array.Length - 1] = ... // insert new value here

Address a single row of a 2-dimensional array?

Is there any way in c# to address a single row of a 2-dimensional array?
I want to be able to pass one-dimension of a 2 dimensional array as a parameter and sometimes I want to pass the whole 2-dimentional array.

You can use jagged arrays.
Example based on the code in Jagged Arrays (C# Programming Guide):
int[][] jaggedArray = new int[3][];
jaggedArray[0] = new int[5];
jaggedArray[1] = new int[4];
jaggedArray[2] = new int[2];
// To pass the whole thing, use jaggedArray
// To pass one of the inner arrays, use jaggedArray[index]