Help extract last change.

February 12th, 2017, 04:47 PM

I have double A be a down arrow sequence, the 3 digit number.
I also have double B be a bar number, the 4 digit number.

As A gets created, it jumps to a new B. (Arrow # might be static but changes to different bar number).

DownArrow: 434 1433
DownArrow: 434 1434
DownArrow: 434 1435
DownArrow: 436 1440
DownArrow: 436 1441
DownArrow: 438 1447
DownArrow: 438 1448
DownArrow: 440 1450
DownArrow: 442 1453
DownArrow: 442 1454
DownArrow: 442 1455

My question is, how do I get the last B of A, before A switches to a new number?

Here is what I want: new arrow list C and new bar number D.

a434 b1435
a436 b1441
a438 b1448
a440 b1450
a442 b1455

So basically, I just want to know what last B is associated with what A.
So that if I run:
if ( C == a436)
{
Print(D);
}
then the output should be
"b1441"

Cheers!

UPDATE:
Would the best approach be index?
if so
how would I get:

C[0] = 1455;
C[1] =1450;
C[2] = 1448;
C[3] =1441;
C[4] = 1435;

February 13th, 2017, 03:00 AM

Something like this mike work.
The mechanism used is a List.

Code

int i;

List<double> C = new List<double>();
List<double> D = new List<double>();

double barnr=0;
for (i=0;i<A.Count()-1;i++)
{
  if (A[i] <> barnr)
   {
     barnr=A[i];
     C.add(A[i]);
     D.add(B[i])
    } 
  else
    {  
     D[D.Count()-1]=B[i];
    }
}

At the end you will end up with two new lists that are reduced
and only hold you last value.

February 13th, 2017, 04:34 AM

rleplae

Something like this mike work.
The mechanism used is a List.

Code

int i;

List<double> C = new List<double>();
List<double> D = new List<double>();

double barnr=0;
for (i=0;i<A.Count()-1;i++)
{
  if (A[i] <> barnr)
   {
     barnr=A[i];
     C.add(A[i]);
     D.add(B[i])
    } 
  else
    {  
     D[D.Count()-1]=B[i];
    }
}

At the end you will end up with two new lists that are reduced
and only hold you last value.

Thanks for the response,
I'm running NT7, and I get the following errors.
1. cannot apply indexing with [] to an expression of type 'int'
2. int does not contain a definition for count and no extension method count accepting first arugument of.....
3. system.collections.generic.list<double> does not contain a definition for add and no extentision....
4. non-invocable member system.collections.generic.list<double>.count cannot be used like a method.

February 13th, 2017, 05:10 AM

victorg20013

Thanks for the response,
I'm running NT7, and I get the following errors.
1. cannot apply indexing with [] to an expression of type 'int'
2. int does not contain a definition for count and no extension method count accepting first arugument of.....
3. system.collections.generic.list<double> does not contain a definition for add and no extentision....
4. non-invocable member system.collections.generic.list<double>.count cannot be used like a method.

The example was 'conceptually', please post your full code if you want advice
are you building a strategy or an indicator ?

February 13th, 2017, 03:56 PM

rleplae

The example was 'conceptually', please post your full code if you want advice
are you building a strategy or an indicator ?

Unfortunately I can't post the code here. its an indi.

February 13th, 2017, 05:48 PM

Just put A and B into a TreeMap (https://docs.oracle.com/javase/8/docs/api/java/util/TreeMap.html) and then use the values() method.

February 13th, 2017, 09:56 PM

Hideyoshi

Just put A and B into a TreeMap and then use the values() method.

I have never used the TreeMap, is it only Java?

February 14th, 2017, 10:34 AM

Yes, it is pure Java. Here is an example which should fit your requirements:

import java.util.TreeMap;
import java.util.Map;

public class Test {

static public void main(String[] args) {
int[] a = {434, 434, 434, 436, 436, 438, 438, 440, 442, 442, 442};
int[] b = {1433, 1434, 1435, 1440, 1441, 1447, 1448, 1450, 1453, 1454, 1455};

TreeMap<Integer,Integer> map = new TreeMap<Integer,Integer>();
for (int i=0; i<a.length; i++) {
map.put(Integer.valueOf(a[i]), Integer.valueOf(b[i]));
}

for (Map.Entry<Integer,Integer> entry : map.entrySet()) {
System.out.println("key ->" + entry.getKey() + ", value->" + entry.getValue());
}
}
}

Result:

key ->434, value->1435
key ->436, value->1441
key ->438, value->1448
key ->440, value->1450
key ->442, value->1455

February 14th, 2017, 12:44 PM

Unfortunately, NinjaScript is in C#. Are there other alternatives?

Help extract last change.

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Help extract last change.