Hello MetaStock’ers,

I have created an external function to read a security’s price information from the metastock database. The function accepts 3 input data structure members:

2. The function uses the MSFL1_ReadDataRec API to read each price record of the security and adds each record to the MSFLPriceRecord_struct array.

   
   

   This seems to work fine, but if I create the MSFLPriceRecord_struct array using the MSFL_MAX_DATA_RECORDS constant for the size, I get a stack overflow error. I have decreased the size to 12000 and the function works fine.

   
   

   I have 15 years worth of data and only seem to be using 5100’ish members of the array, so the size won’t be a problem for a while but it would be nice to have a bullet proof, reusable function to read a security populate a MSFLPriceRecord_struct/MSXDataRec type structure and be able to pass the pointer to different internal functions.

   
   

   Question 1:

   Has anyone written a similar function? Did you fine a way to get around the stack memory error or did you store the security info in a different structure?

   
   

   Question 2:-

   When I run this function in daily mode it works fine, when I run it in weekly the MSFL1_GetSecurityHandle API falls over with message 191 (MSFL_ERR_SECURITY_NOT_FOUND), has anyone experienced this before? Any suggestions on how to correct this?

   
   

   Thanks in advance,
   Shaun

Hey Wabbit,

Thanks for getting back to me. My goal is to create an indicator to perform a relative strength comparison. It will compare the security displayed on the chart to the ‘compare-to’ security passed to the indicator e.g. comparing ANGLO to the gold price, or the gold price to the main index.

I had created this function using the metastock formula language but because I was unable to define the ‘compare-to’ security at runtime (i.e. the ‘input’ function would not allow me to pass a string) I had to create a new indicator each time I wanted to change the ‘compare-to’ security.

So I decided to move the indicator to an external C function and could therefore pass the ‘compare-to’ security to the function (I might still have create a new metastock indictor/explorer to call the external function for each different ‘compare-to’ security but at least I wont have to replicate the relative strength comparison logic).

So the basic logic flow is as follows:-

MetaStock Indicator/Explorer will call the external relative strength comparison function. This function will then perform the following steps:-

• The ‘read compare-to security’ function will accept the security path, symbol, periodicity and a pointer to an array of struct MSFLPriceRecord_struct. It will then perform the following logic:-
  • Perform initialization routines e.g. open the directory, get the handle etc.
  • API to read the first price record
  • array [index]
  • Perform secondary read
    
• Perform routines housekeeping e.g. close the directory, unlock securities etc.

The first problem I have is that if I run this function with periodicity set to ‘D’ it works great, as soon as I change it to ‘W’ the MSFL1_GetSecurityHandle API falls over with message 191 (MSFL_ERR_SECURITY_NOT_FOUND).

Also if I create the size of the MSFLPriceRecord_struct type array? What size you create the array? Or if you did something different?