I am modeling a sort of schedule optimization problem in AMPL and am using gurobi for the option solver.
In this problem, I have declared a set of schedules from 1 through 1000, and called this set "Schedules".
Each schedule sas a sort of layer (a parameter called "layer" has been created) with a value ranging from 1 to 4. This is a sort of preference or hirearchy of the days off that this particular schedule has.
I want several constraints that determine how many schedules of each preference are available. For instance, I want at least 170 of the schedules to have a preference layer of 1. I wrote the following line to do so:
subject to Preference1: sum {j in Schedules: layer[j]=1} >= L1Demand;
Where L1Demand is set to 170. However, when I go to include the model file in the ampl window, I get the following error:
syntax error
context:
subject to Preference1: sum {j in Schedules: layer[j]=1} >>> >= <<< L1Demand;
I don't understand why this is throwing out a syntax error. I may be missing something very basic or obvious, but can anyone tell me as to why this would be happening? Thank you very much.
You should specify an argument for sum, for example:
sum {j in Schedules: layer[j]=1} x[j]
where x is some variable indexed over Schedules.
Related
I'm working on the C++ version of Matt Zucker's Page dewarping. So far everything works fine, but I have a problem with optimization. In line 748 of Github repo Matt uses optimize function from Scipy. My C++ equivalent is find_min_bobyqa from dlib.net. The code is:
auto f = [&](const column_vector& ppts) { return objective( dstpoints, ppts, keypoint_index); };
dlib::find_min_bobyqa(f,
params,
2 * params.nr() + 1, // npt - number of interpolation points: x.size() + 2 <= npt && npt <= (x.size()+1)*(x.size()+2)/2
dlib::uniform_matrix<double>(params.nr(), 1, -2), // lower bound constraint
dlib::uniform_matrix<double>(params.nr(), 1, 2), // upper bound constraint
1, // initial trust region radius
1e-5, // stopping trust region radius
4000 // max number of objective function evaluations
);
In my concrete example params is a dlib::column_vector with double values and length = 189. Every element of params is less than 2.0 and greater than -2.0. Function objective() returns double value and "alone" it works properly because I get the same value as in the Python version. But after running fin_min_bobyqa function I usually get the message:
Terminate called after throwing an instance of 'dlib:bobyqa_failure', return from BOBYQA because the objective function has been called max_f_evals times.
I set max_f_evals to quite big value to see if it optimizes at all, but it doesn't. I did some tweaking with parameters but without good results. How should I set the parameters of find_min_bobyqa to get the right solution?
I am very interested in this issue as well. Zucker's work, with very minor tweaks, is ideal for straightening sheet music images, and I was looking for ways to implement it in a mobile platform when I came across your question.
My research so far suggests that BOBYQA is not the equivalent of Powell's method in scipy. BOBYQA is constrained, and the one in scipy is not.
See these links for more information, and a possible way to compile the right supporting library - I would try UOBYQA or NEWUOA.
https://github.com/jacobwilliams/PowellOpt
https://docs.scipy.org/doc/scipy/reference/generated/scipy.optimize.minimize.html#rdd2e1855725e-3
(See the Notes section)
EDIT: see C version here:
https://github.com/emmt/Algorithms/tree/master/newuoa
I wanted to post this as a comment, but I don't have enough points for that.
I am very interested in your progress. If you're willing, please keep me posted.
I finally solved this problem. I used PRAXIS library, because it doesn't need derivative information and is fast.
I modified the code a little to my needs and now it is faster around few seconds than original version written in Python.
Im new to Report Builder and having issues with some expressions that Im trying to implement in a report. I got the standard ones to work however as soon as I try any distinctions, I get error messages. Over the last couple weeks, Ive tried many combinations, read the expression help, google and looking at other questions at internet sites. To reduce my frustrations, I even would jump to other expressions and walk away hoping I would have different insight coming back.
Its probably something simple or something I dont know about writing expressions.
Im hoping that someone can help with these expressions; they are the versions I get the least errors with(usually just expression expected) and show what Im trying to accomplish.
=IIF((Fields!RECORDFLAG.Value)='D',COUNTDISTINCT(Fields!TICKETNUM.Value),0)
=IIF((Fields!TRANSTYPE.Value)='1' and (Fields!RECORDFLAG.VALUE)='A' or
'B',SUM(Fields!DOLLARS.Value),0)
=IIF((Fields!TRANSTYPE.Value)='1' and
(Fields!RECORDFLAG.VALUE)='P',SUM(Fields!DOLLARS.Value),0)
=Sum([DOLLARS] case when [RECORDFLAG]='P' then -1*[DOLLARS])
Thank You.
=IIF((Fields!RECORDFLAG.Value)=”D”,COUNTDISTINCT(Fields!TICKETNUM.Value))
The error message gives you the answer here - no false part of the iif() has been specified. Use =IIF((Fields!RECORDFLAG.Value)=”D”,COUNTDISTINCT(Fields!TICKETNUM.Value), 0)
=IIF((Fields!TRANSTYPE.Value)="1" and (Fields!RECORDFLAG.VALUE)="A" or "B",SUM(Fields!DOLLARS.Value),0)
This is not how an OR works in SSRS. Use:
=IIF((Fields!TRANSTYPE.Value)="1" and (Fields!RECORDFLAG.VALUE="A" or Fields!RECORDFLAG.Value = "B"),SUM(Fields!DOLLARS.Value),0)
The 0s are returned due to your report design. countdistinct() is an aggregate function - it's meant to be used on a set of data. However, your iif() is only testing on a per row basis - you're basically saying "if the current row is thing, count all the distinct values" which doesn't make sense. There are a couple of ways forward:
You can count the number of times a certain value occurs in a given condition using a sum(). This is not the same as the countdistinct(), but if you use =sum(iif(Fields!RECORDFLAG.Value = "D", 1, 0)) then you will get the number of times RECORDFLAG is D in that set. Note: this requires the data to be aggregated (so in SSRS, grouped in a tablix).
You can use custom code to count distinct values in a set. See https://itsalocke.com/aggregate-on-a-lookup-in-ssrs/. You can apply this even if you have only one dataset - just reference the same one twice.
You can change the way your report works. You can group on Fields!RECORDFLAG.Value and filter the group to where Fields!RECORDFLAG.Value = "D". Then in your textbox, use =countdistinct(Fields!TICKETNUM.Value) to get the distinct values for TICKETNUM when RECORDFLAG is D.
I want to generate a fixed random variable ~N(0,10) for every observation for future computation.
gen X=rnormal (0,10)
list X
Blank
How can I see what value of X is being generated?
You were probably using an empty dataset when you issued these commands. In that case you would first need to tell Stata how many observations your dataset contains. For that you need to use the set obs command, so something like:
. set seed 12345
. set obs 10
obs was 0, now 10
. gen x = rnormal(0,10)
. list, clean
x
1. -9.580833
2. -2.907274
3. 8.45202
4. 8.617108
5. -12.19151
6. 9.457337
7. 1.722469
8. -13.29949
9. -11.5291
10. 25.1646
Think of what would happen when you did not use set obs. In that case Stata would see gen x = rnormal(0,10) and think "ok, I need to create random draws from a normal distribution, but how many?". If you had a dataset open, then it would answer "as many as there are observations in the dataset". If you had no dataset open, then the answer would still be "as many as there are observations in the dataset", but that happens to be 0.
Edit:
If you just want one number you are best of using scalars and not variables. In Stata a scalar refers to a single number and a variable refers to a single column in your dataset. For scalars it is best to use temporary names, as they share the same namespace as variables but variables take precedence when it comes to abreviations, which can lead to unexpected behaviour. So you could do something like:
. tempname a
. scalar `a' = rnormal(0,10)
. di `a'
10.737423
I am attempting to use fortran to write out a comma-delimited file for import into another commercial package. The issue is that I have an unknown number of data columns. My output needs to look like this:
a_string,a_float,a_different_float,float_array_elem1,float_array_elem2,...,float_array_elemn
which would result in something that might look like this:
L1080,546876.23,4325678.21,300.2,150.125,...,0.125
L1090,563245.1,2356345.21,27.1245,...,0.00983
I have three issues. One, I would prefer the elements to be tightly grouped (variable column width), two, I do not know how to define a variable number of array elements in the format statement, and three, the array elements can span a large range--maybe 12 orders of magnitude. The following code conceptually does what I want, but the variable 'n' and the lack of column-width definition throws an error (of course):
WRITE(50,900) linenames(ii),loc(ii,1:2),recon(ii,1:n)
900 FORMAT(A,',',F,',',F,n(',',F))
(I should note that n is fixed at run-time.) The write statement does what I want it to when I do WRITE(50,*), except that it's width-delimited.
I think this thread almost answered my question, but I got quite confused: SO. Right now I have a shell script with awk fixing the issue, but that solution is...inelegant. I could do some manipulation to make the output a string, and then just write it, but I would rather like to avoid that option if at all possible.
I'm doing this in Fortran 90 but I like to try to keep my code as backwards-compatible as possible.
the format close to what you want is f0.3, this will give no spaces and a fixed number of decimal places. I think if you want to also lop off trailing zeros you'll need to do a good bit of work.
The 'n' in your write statement can be larger than the number of data values, so one (old school) approach is to put a big number there, eg 100000. Modern fortran does have some syntax to specify indefinite repeat, i'm sure someone will offer that up.
----edit
the unlimited repeat is as you might guess an asterisk..and is evideltly "brand new" in f2008
In order to make sure that no space occurs between the entries in your line, you can write them separately in character variables and then print them out using theadjustl() function in fortran:
program csv
implicit none
integer, parameter :: dp = kind(1.0d0)
integer, parameter :: nn = 3
real(dp), parameter :: floatarray(nn) = [ -1.0_dp, -2.0_dp, -3.0_dp ]
integer :: ii
character(30) :: buffer(nn+2), myformat
! Create format string with appropriate number of fields.
write(myformat, "(A,I0,A)") "(A,", nn + 2, "(',',A))"
! You should execute the following lines in a loop for every line you want to output
write(buffer(1), "(F20.2)") 1.0_dp ! a_float
write(buffer(2), "(F20.2)") 2.0_dp ! a_different_float
do ii = 1, nn
write(buffer(2+ii), "(F20.3)") floatarray(ii)
end do
write(*, myformat) "a_string", (trim(adjustl(buffer(ii))), ii = 1, nn + 2)
end program csv
The demonstration above is only for one output line, but you can easily write a loop around the appropriate block to execute it for all your output lines. Also, you can choose different numerical format for the different entries, if you wish.
I'd like to calculate the standard deviation over two fields from the same dataset.
example:
MyFields1 = 10, 10
MyFields2 = 20
What I want now, is the standard deviation for (10,10,20), the expected result is 4.7
In SSRS I'd like to have something like this:
=StDevP(Fields!MyField1.Value + Fields!MyField2.Value)
Unfortunately this isn't possible, since (Fields!MyField1.Value + Fields!MyField2.Value) returns a single value and not a list of values. Is there no way to combine two fields from the same dataset into some kind of temporary dataset?
The only solutions I have are:
To create a new Dataset that contains all values from both fields. But this is very annoying because I need about twenty of those and I have six report parameters that need to filter every query. => It's probably getting very slow and annoying to maintain.
Write the formula by hand. But I don't really know how yet. StDevP is not that trivial to me. This is how I did it with Avg which is mathematically simpler:
=(SUM(Fields!MyField1.Value)+SUM(Fields!MyField2.Value))/2
found here: http://social.msdn.microsoft.com/Forums/is/sqlreportingservices/thread/7ff43716-2529-4240-a84d-42ada929020e
Btw. I know that it's odd to make such a calculation, but this is what my customer wants and I have to deliver somehow.
Thanks for any help.
CTDevP is standard deviation.
Such expression works fine for me
=StDevP(Fields!MyField1.Value + Fields!MyField2.Value) but it's deviation from one value (Fields!MyField1.Value + Fields!MyField2.Value) which is always 0.
you can look here for formula:
standard deviation (wiki)
I believe that you need to calculate this for some group (or full dataset), to do this you need set in the CTDevP your scope:
=StDevP(Fields!MyField1.Value + Fields!MyField2.Value, "MyDataSet1")