Syntax error AMPL var

New to AMPL
, ,
1

code1
code11132×1400 350 KB

code2
code21824×1390 375 KB

code3
code31880×1412 261 KB

code4
code41594×1252 201 KB

err3
err31190×442 71.6 KB

Hi,

I am a beginner in using AMPL along with CPLEXto make a MILP model where I am trying to minimise energy consumption. I am testing my model but have run into these errors. I would appreciate any tips or help.

Thank you!

2

Sorry, it’s very hard to work with your screenshot. Please upload Milp.mod: click on Reply, and then click the “uparrow” icon at the top of the editor window to select the file to upload.

3

Milp.mod (11.3 KB)
Hi Robert,

I hope this is okay. Thank you very much!

Shajida

4

I read your model file into AMPL and saw this error:

../Milp.mod, line 114 (offset 5073):
	syntax error
context:  param  >>> CPUs{ <<< s in S}; # Processing request of IOT node s

I couldn’t see anything wrong with the param statement shown in the error message, so I examined your file with a hex editor (HxD) that shows every character code in the file. It revealed that there was a nonprinting character at the end of the previous statement:

image

You can fix this by deleting the line containing the previous statement (param EPId;) and then re-typing the statement.

After that error was fixed, I saw this one:

	s is not defined
context:  var Lsd_mn {(s  >>> in  <<< S), d in D, m in N, n in Nm[m]} >= 0; # Traffic demand between IOT source node s and processing device d  traversing link where m,n

That is caused by putting parentheses ( ) around the indexing expression; it should be

 var Lsd_mn {s in S, d in D, m in N, n in Nm[m]} >= 0; # Traffic demand between IOT source node s and processing device d  traversing link where m,n

But then you will have to do something about the second indexing expression in this statement(d in D) because there is no set D defined in your model.

5

Hi Robert,

Thank you so much, I really appreciate it! I made the corrections you showed but I have ran into some more errors. The second error for Omsd occurs after I comment Psd out which must mean there is consistency in how I have been incorrectly declaring my variables. If possible could you let me know what the issue with my declarations are?
Many thanks,

Shajida
Milp.mod (11.3 KB)

errc
errc1692×460 105 KB

6

It’s the same problem — more nonprinting characters in your model file. To fix each error like “var >>> Psd <<<” you will need to go back to the previous statement (skipping comments) and edit out the nonprinting character. It always comes after the ; character at the end of the previous statement, so you can fix the error by deleting

; #

at the end of the previous statement, and then retyping these characters.