Re: HELP: Reading table from CSV
Thank you.
How could I then pass the values in the table you suggest into the array
LoadPowerProfile{i in LoadsCount, j in PeriodsCount}
On Sat, 05 Dec 2020 13:54:55 + Heinrich Schuchardt
wrote
On 12/5/20 2:11 PM, Manuel Castro wrote:
> Hi all,
>
> First, I would like to thank you for the constant support as you have
> always addressed my questions very promptly.
> Second, I would like to ask you a question as I am really stuck on this one.
>
> I have defined the following in the code:
> set LoadsCount;
> set PeriodsCount;
> param LoadPowerProfile{i in LoadsCount, j in PeriodsCount};
>
> For the sake of discussion let's assume that "LoadsCount" is 1..100 and
> "PeriodsCount" is 1..8760 (i.e. hourly values through the year).
> I now want to fill in my array "LoadPowerProfile" with values. For that
> I have the following table in CSV (of course this is a stylized table
> just for you to understand what I am up to).
With the GLPK you cannot read cross-tabulated CSV files.
You should create a table where you have separate columns for load,
hour, value.
Load,Hour,Value
1,0,3.4
1,1,5.7
...
100,8760,6.7
Best regards
Heinrich
>
> Load
> 1
> 2
> (…)
> 8760
> Load1
> 11.98
> 62.51
>
> 99.69
> Load2
> 86.39
> 59.50
>
> 25.89
> (...)
>
>
>
>
> Load100
> 67.98
> 98.71
>
> 31.19
>
>
> How do I read the yellow shaded area into my "LoadPowerProfile" array? I
> would be thankful if you could give me an example of the statement i
> should use to read this into "LoadPowerProfile" array.
>
> Many thanks in advance for all your support.
>
> Kind regards,
> Manuel.
>
HELP: Reading table from CSV
Hi all,
First, I would like to thank you for the constant support as you have always
addressed my questions very promptly.
Second, I would like to ask you a question as I am really stuck on this one.
I have defined the following in the code:
set LoadsCount;
set PeriodsCount;
param LoadPowerProfile{i in LoadsCount, j in PeriodsCount};
For the sake of discussion let's assume that "LoadsCount" is 1..100 and
"PeriodsCount" is 1..8760 (i.e. hourly values through the year).
I now want to fill in my array "LoadPowerProfile" with values. For that I have
the following table in CSV (of course this is a stylized table just for you to
understand what I am up to).
Load
1
2
(…)
8760
Load1
11.98
62.51
99.69
Load2
86.39
59.50
25.89
(...)
Load100
67.98
98.71
31.19
How do I read the yellow shaded area into my "LoadPowerProfile" array? I would
be thankful if you could give me an example of the statement i should use to
read this into "LoadPowerProfile" array.
Many thanks in advance for all your support.
Kind regards,
Manuel.
Help: “current directory” function
Hi glpk wizards, I wonder if there a kind of function or workaround that returns the directory path of where the ‘.mod’ file is?? Basically in the folder where the ‘.mod’ file is, I have created another folder called “data” where I have all my input and output CSV data files. I can insert this directory path as a string in the GLPK reading CSV file statement. But of course if I change the directory of the project then, I have to go to the ‘.mod’ file and rewrite the directory path which is very inconvenient. So, is there a function/workaround that can return the directory path of the ‘mod’ file? Many thanks for your help. Kind regards, Manuel.
Help “current directory” function
Hi glpk wizards,I wonder if there a kind of function or workaround that returns the directory path of where the ‘.mod’ file is??Basically in the folder where the ‘.mod’ file is, I have created another folder called “data” where I have all my input and output CSV data files. I can insert this directory path as a string in the GLPK reading CSV file statement. But of course if I change the directory of the project then, I have to go to the ‘.mod’ file and rewrite the directory path which is very inconvenient. So, is there a function/workaround that can return the directory path of the ‘mod’ file?Many thanks for your help.Kind regards,Manuel.
Help: read single value from CSV
Hi there,
What does the syntax statement look like to read a single value from the CSV
file?
My CSV has the following:
RowIndex Capacity
1 33
I read it as follows:
param Z {i in I};
table tab_stream IN "CSV" "stream.csv" : [RowIndex], Z ~ Capacity;
I am only interested in the column 'Capacity', i.e. in the value 33.
More importantly, I don't need Z to be an array. I want Z to be a scalar i.e.
param Z;
How do I represent this in the read statement of the CSV?
Many thanks.
Kind regards,
Manuel.
Help: read from txt files
Hi there, Is it possible to get GLPK to read/write data from/to text files? If yes: what is the syntax statement one should use for that purpose? what is the format the input data in the text file should be in? Many thanks in advance for your help. It's really appreciated. Kind regards, Manuel.
Help: Switching between different objective function
Hi there,
I am wondering how I can use an if statement to switch between different
objective functions.
For example, how do I represent the following:
If (StatusFlag_X == 1 && StatusFlag_Y == 0) then
minimize cost: sum{i in I, j in J} c[i,j] * x[i,j];
end if
If (StatusFlag_X == 0 && StatusFlag_Y == 1) then
minimize cost: sum{i in I, j in J} c[i,j] * x[i,j] + d[i,j] * Y[i,j];
end if
Both are mutually exclusive, i.e. either you do one or the other, i.e. both
objective functions will never be activate at the same time
This is what I used to do in "mosel" language from FICO Xpress (I don't have a
license anymore so I am discovering GLPK ). How can I do this in GLPK language?
What's the workaround that we can use for this?
Many thanks in advance for your help. It's really appreciated.
Kind regards,
Manuel.
Re: Help: Switch constraints on or off
Hi Andrew,Thank you for the prompt reply.What do you mean by C
prepocessor?? Apologies, I know how to program but that’s pretty much it...
On Tue, 24 Nov 2020 19:42:10 + m...@gnu.org wrote On
Tue, 2020-11-24 at 18:59 +, Manuel Castro wrote: > Hi there, > > I am
wondering how I can use an if statement to turn a constraint on > or off. > For
example in my problem I have the following constraint: > > subject to linctr14
{i in PeriodsCount: i == 1}: StorageEnergy[i] = > (StorageStateCharge *
StorageEnergyRating + ((StorageEfficiencyCharge > * (StoragePowerCharge[i])) -
((StoragePowerDischarge[i]) / > StorageEfficiencyDischarge))); > > Now, I only
want to consider storage in my problem if an object > storage actually exists.
> For that, I would have a StorageStatusFlag which if equal to "1" then > I
would consider the constraint in my problem. > For example: > > If
(StorageStatusFlag == 1) then > subject to linctr14 {i in PeriodsCount: i
== 1}: StorageEnergy[i] > = (StorageStateCharge * StorageEnergyRating + >
((StorageEfficiencyCharge * (StoragePowerCharge[i])) - >
((StoragePowerDischarge[i]) / StorageEfficiencyDischarge))); > end if > > This
is what I used to do in "mosel" language from FICO Xpress (I > don't have a
license anymore so I am discovering GLPK ). How can I do > this in GLPK
language? What's the workaround that we can use for this? You could use the C
preprocessor. > > Many thanks in advance for your help. It's really
appreciated. > > Kind regards, > Manuel. >
Change Path Input/Output file
Hi there, I am currently using gusek as an IDE to model and run GLPK. I use the following statement to read from CSV file. table tab_plant IN "CSV" "plants.csv" : I <- [plant], a ~ capacity; This assumes that the file is placed in the same directory where the glpk solver is. How can I place my CSV file in a different directory and tell glpk to read it from there? How do I add the path on my model syntax? Many thanks in advance for your help. It's really appreciated. Kind regards, Manuel.
Help: Switch constraints on or off
Hi there,
I am wondering how I can use an if statement to turn a constraint on or off.
For example in my problem I have the following constraint:
subject to linctr14 {i in PeriodsCount: i == 1}: StorageEnergy[i] =
(StorageStateCharge * StorageEnergyRating + ((StorageEfficiencyCharge *
(StoragePowerCharge[i])) - ((StoragePowerDischarge[i]) /
StorageEfficiencyDischarge)));
Now, I only want to consider storage in my problem if an object storage
actually exists.
For that, I would have a StorageStatusFlag which if equal to "1" then I would
consider the constraint in my problem.
For example:
If (StorageStatusFlag == 1) then
subject to linctr14 {i in PeriodsCount: i == 1}: StorageEnergy[i] =
(StorageStateCharge * StorageEnergyRating + ((StorageEfficiencyCharge *
(StoragePowerCharge[i])) - ((StoragePowerDischarge[i]) /
StorageEfficiencyDischarge)));
end if
This is what I used to do in "mosel" language from FICO Xpress (I don't have a
license anymore so I am discovering GLPK ). How can I do this in GLPK language?
What's the workaround that we can use for this?
Many thanks in advance for your help. It's really appreciated.
Kind regards,
Manuel.
