Search found 29 matches

by Dr John P Weldon
Thu Feb 25, 2021 3:39 am
Forum: Vensim
Topic: What improvements would you like to see in Vensim?
Replies: 120
Views: 82083

Re: What improvements would you like to see in Vensim?

Some changes to Vensim are disruptive and extensive. 'COMPREAL' is the most-recent example. Currently, users are provided with a template project, and are then expected to rebuild their own projects from scratch. There are various circumstances and reasons why this approach is undesirable and even s...
by Dr John P Weldon
Thu Feb 25, 2021 3:28 am
Forum: Vensim
Topic: What improvements would you like to see in Vensim?
Replies: 120
Views: 82083

How best to respond to changes in Vensim

Some changes to Vensim are disruptive and extensive. 'COMPREAL' is the most-recent example. Currently, users are provided with a template project, and are then expected to rebuild their own projects from scratch. There are various circumstances and reasons why this approach is undesirable and even s...
by Dr John P Weldon
Thu Feb 04, 2021 5:06 am
Forum: Vensim
Topic: COMPREAL v float and REAL
Replies: 19
Views: 1621

Re: COMPREAL v float and REAL

By 'the function' I assume that you refer to the subprogram: in this case paramid4.c. I changed its declaration to COMPREAL /*FUNCTION*/ PARAMID4( ... The declarations of function PARAMID4 in venext.c are extern COMPREAL PARAMID4(DATAP INVAR, DATAP ONDTM, DATAP OSTTM, DATAP XNDTM, DATAP XSTTM, COMPR...
by Dr John P Weldon
Wed Feb 03, 2021 8:20 pm
Forum: Vensim
Topic: COMPREAL v float and REAL
Replies: 19
Views: 1621

Re: COMPREAL v float and REAL

One type of warning that appears often is 1>c:\vensim\venext6\external sub functions\hospital\paramid4.c(663): warning C4244: 'return': conversion from 'COMPREAL' to 'REAL', possible loss of data COMPREAL paramid4_v; if( EQUAL(type, ONE)){ // integer array paramid4_v = (COMPREAL)entout4[ndm1 - 1][nd...
by Dr John P Weldon
Mon Feb 01, 2021 7:03 am
Forum: Vensim
Topic: COMPREAL v float and REAL
Replies: 19
Views: 1621

Re: COMPREAL v float and REAL

I changed all extern REALs to double, to conform with the sample venext.c. That did not work. Same warnings as before. I then changed all extern REALs to extern COMPREALs. That did not work either. Following your latest advice I changed all internal REALs in ADJTM.c to COMPREAL. In venext.c (extern ...
by Dr John P Weldon
Mon Feb 01, 2021 1:57 am
Forum: Vensim
Topic: COMPREAL v float and REAL
Replies: 19
Views: 1621

Re: COMPREAL v float and REAL

I always welcome simple solutions. However, there are apparently no REAL instances to replace in venext.c, particularly in the 'case' section of venext.c where all the COMPREAL warnings occur. Am I misunderstanding you in some way?
by Dr John P Weldon
Sun Jan 31, 2021 11:14 pm
Forum: Vensim
Topic: COMPREAL v float and REAL
Replies: 19
Views: 1621

Re: COMPREAL v float and REAL

It is not sufficiently evident from the sample venext.c what the new version of my ADJTM.C etc. should look like. I should therefore be obliged if somebody could translate ADJTM.C into that new version. I could then use the 'template' to convert the remaining 130 plus instances. In my models an exam...
by Dr John P Weldon
Fri Jan 29, 2021 7:02 am
Forum: Vensim
Topic: Memory allocation failure - subblock
Replies: 15
Views: 1225

Re: Memory allocation failure - subblock

For my work in developing models 32bit will probably always suffice. My objective has been to confirm that one particular application will run under Vensim 8.1 and Visual Studio 2017. When that application is used by others the 64bit version may be needed. I have not yet tried to run the application...
by Dr John P Weldon
Thu Jan 28, 2021 1:06 pm
Forum: Vensim
Topic: Memory allocation failure - subblock
Replies: 15
Views: 1225

Re: Memory allocation failure - subblock

Reference 'tomfid' Your first paragraph has already been contradicted -- by a previous one-off or particular allocation of additional memory to another user. I am not asking for a generic anything; only the same treatment as that provided to the other user. Your second paragraph seeks to ignore the ...
by Dr John P Weldon
Thu Jan 28, 2021 4:40 am
Forum: Vensim
Topic: Memory allocation failure - subblock
Replies: 15
Views: 1225

Re: Memory allocation failure - subblock

I received files from the administrator on 9 April 2020. Those files would then have been processed for use as external function subprograms and compilation into a DLL. The error message 'memory allocation failure - subblock' appears when I try to load a model into the Vensim screen. The message mea...
by Dr John P Weldon
Tue Jan 26, 2021 10:17 am
Forum: Vensim
Topic: Memory allocation failure - subblock
Replies: 15
Views: 1225

Re: Memory allocation failure - subblock

With reference to 'administrator' It is impossible to remove all calls to subprograms. But, as many of them as possible were removed, and those calls remaining are also made in the two smaller models. Those use the same DLL and run without problem. In that sense the answer to your question is 'no'. ...
by Dr John P Weldon
Tue Jan 26, 2021 7:24 am
Forum: Vensim
Topic: Memory allocation failure - subblock
Replies: 15
Views: 1225

Re: Memory allocation failure - subblock

With reference to 'tomfid'. I am using x86 (32 bit). In my experience life has become more difficult the higher the Vensim edition (from about v7.0). I do not wish to change editions until the memory allocation failure problem has been resolved. The same problem for 'rossen' was evidently resolved w...
by Dr John P Weldon
Tue Jan 26, 2021 12:05 am
Forum: Vensim
Topic: Memory allocation failure - subblock
Replies: 15
Views: 1225

Memory allocation failure - subblock

On Tuesday 7 January 2020 'rossen', a registered member of the Vensim forum, reported that he was experiencing the error message 'Memory allocation failure - subblock'. On the same day the forum's administrator responded: 'I'll see if I can enable more memory for this'. The administrator was not ask...
by Dr John P Weldon
Mon Jan 25, 2021 9:39 pm
Forum: Vensim
Topic: COMPREAL v float and REAL
Replies: 19
Views: 1621

Re: COMPREAL v float and REAL

I have already informed the forum that I was also told initially that a sample venext.c file that ships with Vensim would assist in resolving my problem. No sample venext.c file has been found on my hard disk that can do that. Please copy this sample venext.c file to me. Perhaps I can then resolve t...
by Dr John P Weldon
Mon Jan 25, 2021 11:05 am
Forum: Vensim
Topic: COMPREAL v float and REAL
Replies: 19
Views: 1621

Re: COMPREAL v float and REAL

double rval=0.0; case ADJTM_FUNC : rval = ADJTM(val[0].vec->vals, (L1150) val[1].vec->vals, val[2].vec->vals, val[3].val, val[4].val, val[5].val, val[6].val, val[7].val, val[8].val, val[9].val, val[10].val); (L1160) break; Warnings 1>..\Venext6\External Sub Functions\hospital\Venext.c(1150): warning...
by Dr John P Weldon
Thu Jan 07, 2021 3:16 am
Forum: Vensim
Topic: Model validation
Replies: 1
Views: 305

Model validation

I have a SD model that can be used for management control and tactical/strategic planning etc. by a large number of actual instances of the one system type. Differences between those instances are believed to be confined to their input data. The question arises: for how many instances should the mod...
by Dr John P Weldon
Tue Dec 29, 2020 7:07 am
Forum: Vensim
Topic: COMPREAL v float and REAL
Replies: 19
Views: 1621

COMPREAL v float and REAL

Venext.c val[2].vec->vals, (1128) val[3].val, (1129) 1>c:\vensim\venext6\external sub functions\hospital\venext.c(1128): warning C4133: 'function': incompatible types - from 'COMPREAL *' to 'float *' 1>c:\vensim\venext6\external sub functions\hospital\venext.c(1129): warning C4244: 'function': conve...
by Dr John P Weldon
Mon Dec 21, 2020 4:28 am
Forum: Vensim
Topic: Sample venext.c file
Replies: 1
Views: 327

Sample venext.c file

I am a registered user of DSS v8.1.0. I need to access the sample venext.c file, but cannot find it on my hard drive. Could you please tell me how to access it, or copy it to me at abbeylane21@outlook.com.
by Dr John P Weldon
Thu Dec 03, 2020 3:48 am
Forum: System Dynamics Discussion
Topic: Model validation
Replies: 1
Views: 491

Model validation

There is a model that applies to all instances of the system type modelled. Differences between individual instances are entirely attributable to input data (numbers). In this situation what will constitute sufficient validation in terms of the number of individual instances validated? One instance;...
by Dr John P Weldon
Mon Aug 03, 2020 11:55 pm
Forum: Vensim
Topic: MS C/C++ DLLs for Vensim DSS models
Replies: 6
Views: 1160

Re: MS C/C++ DLLs for Vensim DSS models

When you earlier recompiled the DLL for me I was using Visual Studio 2008 and DSS version 7.2. Now I am using VS 2017 and DSS v8.1.0. After implementing advice in the past 24 hours from Administrator Tomfid, I have advanced to 'External function version mismatch need version 62051 (got 62050)' for o...
by Dr John P Weldon
Sat Aug 01, 2020 6:42 am
Forum: Vensim
Topic: MS C/C++ DLLs for Vensim DSS models
Replies: 6
Views: 1160

MS C/C++ DLLs for Vensim DSS models

I am using Vensim DSS v8.1.0 with Visual Studio 2017 in Windows 10. Do I still have the option of writing subprograms in MS C? Or, must they be written in C++? When I double-click on the Vensim icon on the desktop I get a message (before any model is loaded): External function version mismatch need ...
by Dr John P Weldon
Mon Apr 06, 2020 1:01 am
Forum: Vensim
Topic: External function version mismatch
Replies: 12
Views: 2342

Re: External function version mismatch

I included _VDFX in preprocessor definitions. No improvement resulted. I have looked at the template venext.c in c:\users\... Many choices and decisions will need to be made, in aligning my existing venext.c with the new one. I would not feel confident in making those choices and decisions. Can you ...
by Dr John P Weldon
Sun Apr 05, 2020 1:33 pm
Forum: Vensim
Topic: External function version mismatch
Replies: 12
Views: 2342

Re: External function version mismatch

I defined VDF and _VDFX in venext.c and recompiled the DLL. Those definitions made a negative difference to the outcome: 'the external functions in [the DLL] could not be loaded'. I was shut out, until I stated that the DLL should not be loaded next time. Should I remove the above definitions, or do...
by Dr John P Weldon
Sun Apr 05, 2020 4:10 am
Forum: Vensim
Topic: External function version mismatch
Replies: 12
Views: 2342

Re: External function version mismatch

_VDFX is mentioned in the Vensim context only in platform_specific.h. In this file _VDFX is defined only #ifdef _WIN64. I am not using WIN64, as far as I know. Each of my applications has a dedicated venext.c. Beyond those I am unsure which is the file that is shipped with Vensim. I have selected a ...
by Dr John P Weldon
Sat Apr 04, 2020 5:09 am
Forum: Vensim
Topic: External function version mismatch
Replies: 12
Views: 2342

Re: External function version mismatch

Vensim.h is apparently the only Vensim-type header file in my subprograms. I made the latest version of vensim.h available to those subprograms. When I recompiled the DLL I got error C2039 in venext.c: 'tot_vol' is not a member of 'tag_dim_info_vdf'. 'tot_vol' is in static void validate_vector_arg(V...