Is there a way to "die" in execution flow in an xquery file and output a nicely formatted printout of a sequence variable?
I'm trying something like:
return { fn:error(xs:QName("ERROR"), $xml) }
but that doesn't quite seem to work.
Thanks!
Based on your comment (you need it for debugging) I guess you are looking for the fn:trace function, described here http://www.xqueryfunctions.com/xq/fn_trace.html
If you want to abort the execution flow and output an error in your application you should in fact use the XQuery exception handling.
Try something like this, omitting the return if this isn't part of a FLWOR expression.
...
return fn:error((), "DEBUG", $xml)
There's no need for curly braces unless you're enclosing an expression, for example <x>{ current-time() }</x>. The return expression is not enclosed.
With MarkLogic it's best to leave the first parameter of fn:error empty. That way you don't have to worry about a QName, and anyway some folks believe that it's reserved for predefined errors. MarkLogic uses the second parameter to fill in error:code, and the third parameter for data.
For more on fn:error, see http://docs.marklogic.com/fn:error and https://github.com/robwhitby/xray/pull/11
Related
I have a command with six lines that I want to use several times. Therfore, I want to assign a name to this command and use it as a procedure instead of writing the whole command lines over and over.
In this case it is a <-rbind() command, but the issue is also more general.
modelcoeff<-rbind(modelcoeff,c(as.character((summary(mymodel)$terms[[2]])[[3]]),
as.character((((((summary(mymodel)$terms[[2]])[[2]])[[3]])[[3]])[[2]])[[3]]),
summary(mymodel)$coefficients[2,1],
summary(mymodel)$coefficients[2,4],
summary(mymodel)$coefficients[2,2],
summary(mymodel)$r.squared*100))
I would like to call something like rbindmodelcoeff and execute these command lines. How can I achieve this?
I tried to write a function, but it didn't seem to be the right approach.
A literal wrapping of your code into a function:
rbindmodelcoeff <- function(modelcoeff, mymodel) {
rbind(modelcoeff,
c(as.character((summary(mymodel)$terms[[2]])[[3]]),
as.character((((((summary(mymodel)$terms[[2]])[[2]])[[3]])[[3]])[[2]])[[3]]),
summary(mymodel)$coefficients[2,1],
summary(mymodel)$coefficients[2,4],
summary(mymodel)$coefficients[2,2],
summary(mymodel)$r.squared*100))
}
However, there are a couple changes I recommend:
call summary(mymodel) once, then re-use the results
you are using as.character on some of the objects but not all within the enclosing c(.), so everything is being converted to a character; to see what I mean, try c(as.character(1), 2); we can use a list instead to preserve string-vs-number
rbindmodelcoeff <- function(modelcoeff, mymodel) {
summ <- summary(mymodel)
rbind(modelcoeff,
list(as.character((summ$terms[[2]])[[3]]),
as.character((((((summ$terms[[2]])[[2]])[[3]])[[3]])[[2]])[[3]]),
summ$coefficients[2,1],
summ$coefficients[2,4],
summ$coefficients[2,2],
summ$r.squared*100))
}
But there are still some problems with this. I can't get it to work at the moment since I don't know the model parameters you're using, so as.character((summ$terms[[2]])[[3]]) for me will fail. With that, I'm always hesitant to hard-code so many brackets without a firm understanding of what is being used. It's out of scope for this question (which is being converting your basic code into a function), but you might want to find out how to generalize that portion a bit.
I'm trying to package some code I use for data analysis so that other workers can use it. Currently, I'm stuck trying to write a simple function that imports data from a specific file type generated by a datalogger and trims it for use by other functions. Here's the code:
import<-function(filename,type="campbell",nprobes){
if (filename==TRUE){
if (type=="campbell"){
message("File import type is from Campbell CR1000")
flux.data<<-read.table(filename,sep=",",header=T,skip=1)
flux.data<<-flux.data[,-c(1,2)];flux.data<<-flux.data[-c(1,2),]
if (nprobes=="missing"){
nprobes<-32
}
flux.data<<-flux.data[,c(1:nprobes)]
flux.data.names<<-colnames(flux.data) #Saves column names
}
}
}
Ideally, the result would be a dataframe/matrix flux.data and a concomittant vector/list of the preserved column headers flux.data.names. The code runs and the function executes without errors, but the outputs aren't preserved. I usually use <<- to get around the function enclosure but its not working in this case - any suggestions?
I think the real problem is that I don't quite understand how enclosures work, despite a lot of reading... should I be using environment to assign environments within the function?
User joran answered my question in the comments above:
The critical issue was just in how the function was written: the conditional at the start (if filename==TRUE) was intended to see if filename was specified, and instead was checking to see if it literally equaled TRUE. The result was the conditional never being met, and no function output. Here's what fixed it:
import<-function(filename,type="campbell",nprobes){
if (exists(filename){
if (type=="campbell"){
#etc....
Another cool thing he pointed out was that I didn't need the <<- operator to utilize the function output and instead could write return(flux.data). This is a much more flexible approach, and helped me understand function enclosures a lot better.
Now I'm making an endless runner where objects are spawned in front on me randomly.
I was told to make a spawnController and globalController object, so I did. Then this code should be put in the controller under step event
if(tick = 32)
{
tick = 0;
instance_create(room_width,room_height,random(spike,groundBlock));
instance_create(room_width,irandom_range(0,room_height-32));
}
tick += 1;
Is there anything wrong with it because i get an error, which is:
In object spawnController, event Step, action 1 at line 4: Wrong number of arguments to function or script.
instance_create(room_width,irandom_range(0,room_height-32));
The error messages in GM can sometimes be a bit unclear.. But in this case it was pretty clear. It goes about this line. And one of the scripts has too few arguments. Either irandom_range or instance_create you forgot an argument.
irandom_range takes two arguments to make a random number, so that is correct.
instance_create however takes 3 arguments: x,y position and the object from which you wish to create an instance. You're simply missing that argument (and the error tells you that). I think that is a typo as you do it correctly in the creation above.
Manual about instance_create
You have a syntax error here:
instance_create(room_width,irandom_range(0,room_height-32);
There's no closing parentheses or a 3rd argument.
One thing that stood out to me is that you used random instead of choose. Im not sure there is a difference in this situation, but choose allows you to list as many arguments you want.
But the other thing as was pointed out, was that your missing the object you want the 4th life to create. You need to specify what object you want it to make.
instance_create(room_width, irandom_range(0,room_height-32), OBJECT);
Suppose I have a function that has multiple returned values (shown below). However, this output is not informative as users do not know what each value stands for unless they look up the function definition. So I would like to use println() to print the results with appropriate names to the screen, while suppressing the the actual returned values from being printed on the screen. In R, the function invisible() does that, but how do you do the same thing in Julia?
function trimci(x::Array; tr=0.2, alpha=0.05, nullvalue=0)
se=sqrt(winvar(x,tr=tr))./((1-2.*tr)*sqrt(length(x)))
ci=cell(2)
df=length(x)-2.*floor(tr.*length(x))-1
ci=[tmean(x, tr=tr)-qt(1-alpha./2, df).*se, tmean(x, tr=tr)+qt(1-alpha./2, df).*se]
test=(tmean(x,tr=tr)-nullvalue)./se
sig=2.*(1-pt(abs(test),df))
return ci, tmean(x, tr=tr), test, se, sig
end
In addition to what Harlan and Stefan said, let me share an example from the ODBC.jl package (source here).
One of my favorite features of Julia over other languages is how dead simple it is to create custom types (and without performance issues either!). Here's a custom type, Metadata, that simply holds several fields of data that describe an executed query. This doesn't necessarily need its own type, but it makes it more convenient passing all this data between functions as well as allowing custom formatting of its output by overloading the Base.show() function.
type Metadata
querystring::String
cols::Int
rows::Int
colnames::Array{ASCIIString}
coltypes::Array{(String,Int16)}
colsizes::Array{Int}
coldigits::Array{Int16}
colnulls::Array{Int16}
end
function show(io::IO,meta::Metadata)
if meta == null_meta
print(io,"No metadata")
else
println(io,"Resultset metadata for executed query")
println(io,"------------------------------------")
println(io,"Columns: $(meta.cols)")
println(io,"Rows: $(meta.rows)")
println(io,"Column Names: $(meta.colnames)")
println(io,"Column Types: $(meta.coltypes)")
println(io,"Column Sizes: $(meta.colsizes)")
println(io,"Column Digits: $(meta.coldigits)")
println(io,"Column Nullable: $(meta.colnulls)")
print(io,"Query: $(meta.querystring)")
end
end
Again, nothing fancy, but illustrates how easy it really is to define a custom type and produce custom output along with it.
Cheers.
One thing you could do would be to define a new type for the return value for this function, call it TrimCIResult or something. Then you could define appropriate methods to show that object in the REPL. Or you may be able to generalize that solution with a type hierarchy that could be used for storing the results from and displaying any statistical test.
The value nothing is how you return a value that won't print: the repl specifically checks for the value nothing and prints nothing if that's the value returned by an expression. What you're looking to do is to return a bunch of values and not print them, which strikes me as rather odd. If a function returns some stuff, I want to know about it – having the repl lie to users seems like a bad idea. Harlan's suggesting would work though: define a type for this value with the values you don't want to expose to the user as fields and customize its printing so that the fields you don't want to show people aren't printed.
I try to evaluate a field in my report but it fails every time :
= IIf(Fields!lectcrs_hrs.IsMissing,
Round(Fields!lectcrs_fee.Value * "1.00", 2),
Round(Fields!lectcrs_fee.Value * Fields!lectcrs_hrs.Value, 2))
in the case of Fields!lectcrs_hrs.IsMissing = true my field is empty and i find that the reason that the second case Round(Fields!lectcrs_fee.Value * Fields!lectcrs_hrs.Value, 2) contains a missing field Fields!lectcrs_hrs .why it checks the second case if it passes the first one !
How to fix this problem ?
The behavior you are looking for is called "short-circuiting" and, unfortunately, the IIf function in Visual Basic does not offer that. The reason being is that IIf() is a ternary function and, as such, all arguments passed into it are evaluated before the function call occurs. A ternary operator (If() in VB 9+), on the other hand, does support conditional evaluation. However, I do not believe that the If() operator can be used as a part of an expression in SSRS.
Given the fact that you are trying to use a field which may or may not exist at run time, I suggest that you create a custom function in your report to handle the proper checking and return values. For reference, take a look at this blog post, which covers the same scenario.