- #42
- Nov 20, 2010 7:32am Nov 20, 2010 7:32am
- Joined Oct 2008 | Status: Sailing for pips | 2,099 Posts
- #44
- Nov 20, 2010 9:30am Nov 20, 2010 9:30am
- Joined Oct 2008 | Status: Sailing for pips | 2,099 Posts
- #45
- Nov 20, 2010 9:36am Nov 20, 2010 9:36am
- Joined Oct 2008 | Status: Sailing for pips | 2,099 Posts
- #47
- Nov 20, 2010 12:16pm Nov 20, 2010 12:16pm
- Joined Oct 2008 | Status: Sailing for pips | 2,099 Posts
- #50
- Nov 24, 2010 11:40pm Nov 24, 2010 11:40pm
- Joined Oct 2009 | Status: . | 4,038 Posts
It needs ticks to trigger the start() function. There are scripts that can simulate this on weekends.
For example this to send a continuous stream of ticks to the chart:
[code]
/**
* MT4/experts/scripts/ticks.mq4
* send a fake tick every 200 ms to the chart and
* all its indicators and EA until this script is removed.
*/
#property copyright "Bernd Kreuss"
#import "user32.dll"...
question 1 : can this be used to 'create' a fake symbol and then stream data to it? an outside program could be set up as the 'server' sending fake data internally?
or, you could stream fake data to an unused exotic symbol you would never actually want to trade but can load into mt4... that way you aren't breaking any data on your real-traded charts.
question 2 : can this be used to set a custom spread? (or was that the point and i'm too tired to realise?)
Congratulations ScalaFX for coming out of the closet!
- #57
- Edited 4:43am Sep 18, 2011 3:29am | Edited 4:43am
- Joined Mar 2009 | Status: Trader | 1,231 Posts
7Bit, great job on creating mt4R.dll. I have cobbled up a wrapper for VB6
The two matrix routines RAssignMatrix and RAppendMatrixRow are giving me problems. It may be that VB6 and Pascal matrix structures are incompatible for multi-dimensional arrays, or more likely that my infantile understanding of R / Pascal and how they handle arrays/matrices is the problem. Case in point: I don't even know how to check matrix / vector bounds within R.
In C it would be a double * foo and you could dereference it with foo[x], in Pascal you essentially do the same with a foo
Double, the syntax is different (easier for humans, more natural, more straightforward, less ambiguous) the representation on the machine level is exactly the same as the equivalent in C.The matrix (or 2-dimensional array) for example:
1 2 3
4 5 6
7 8 9
would be represented in memory just like a flat 1-d array:
1 2 3 4 5 6 7 8 9 (at this point without looking into the code now from the top of my head I am not 100% sure it could also be transposed):
1 4 7 2 5 8 3 6 9 (but this can easily be found out)
and in fact in my dll I am passing 2d arrays as 1d arrays along with two variables defining the row and column count.
Passing an array (no matter how many dimensions) to the dll from mql4 means passing the pointer to a memory block containing such a flat row of numbers, each number as 8 byte double, no header, no separators, just the numbers. The above example matrix of 9 elements would be passed as a pointer to a block of memory of 72 bytes length. An 1D array would look exactly the same, its just the additional information about row and column count that tells my code how to read it.
I'm not sure how in VB a 2D array is organized, if it works the same way it should be possible there too. If in VB the 2D arrays are somehow more complicated structures than described above then you could also try to make the matrix a one dimensional array and pass that to RAssignMatrix along with the row and column count.
I figured a workaround using RAssignVector, and then combining a temporary vector into an already dimensioned matrix in R one column at a time:copies tempA to column 1 of multiA. Repeated in a loop, this approximates the functionality of RAssignMatrix.Inserted CodeRx("multiA[,1] <- tempA")
It appears that RRowBindVector(), which is mentioned in the RAssignMatrix comments of mt4R.mqh is not found in the mt4R.dll source code.
___
[edit:] double has only 8 bytes of course, I confused it with something else. One can easily forget (and even safely ignore) this if using a language with strong typing and typed pointers and not being forced to mess around with void pointers all day long.