I'd like to be able to pass a 'format' into a Fortran subroutine. Take this example:
write(6,1002) M1
1002 format(A, "M1, Mach number at boundary layer edge", f8.3)
For reasons too involved to go into here it would be useful to have a generic function to which I send a variable with a format statement that would be used to write out. I can't figure out a way of doing this.
Any ideas?
You can't really pass a format statement to a subroutine. But you can pass a format string, something like:
fmtstr = '(A, "M1, Mach number at boundary layer edge", f8.3)'
...
call mysub(args, fmtstr)
then
subroutine mysub(args, fmtstr)
...
character(*), intent(in) :: fmtstr
...
write(*,fmtstr) M1
end subroutine
Some might argue that format strings are the best modern way to handle formats in all circumstances and have retired their use of format statements entirely.
Forget FORMAT statements, use format strings
string = '(A, "M1, Mach number at boundary layer edge", f8.3)'
write(*,string) M1
You can pass strings easily to a subroutine.
Format statements are just obsolete and awkward to work with.
Also, do not use unit number 6, but *, that is much more portable.
Related
IC=IC
ACC=ACC
v_statement='ACC = '1052502',0.035,IC = 'IC130',0.0675'
v_decode_out=DECODE(TRUE,v_statement,0)
i am getting error
is the above expression correct.Is there anyway we can achieve this
There are two problems in your query
First, the v_statement variable you have written won't be validated. If you
really want to write a string in this format, then use pipes to append as
'ACC='||1052502||','||0.035||'IC='||'IC130'||','||'0.0675'
Note that you cannot loop quotes.
Second, the reason your decode statement wont work is because of the data type mismatch. True is a boolean value and v_statement is a string. Any variable expansion would happen during run time but not before that. So, informatica does not allow you this kind of decode statement, unless you are comparing some kind of string input/variable with another string or any other data type for that matter
Also, decide on your case
When it is If ACC else IC to be evaluated (this seems to be your case)
v_decode_out=DECODE(ACC,'1052502',0.035,DECODE(IC,'IC130',0.0675))
When it is both ACC and IC together
v_decode_out=DECODE(TRUE,ACC='1052502' and/or IC='IC130',0.035,0.0675)
These are fundamental concepts. It's advisable that you try out everything available on internet before you post a question here, because someone could easily down rate you if they feel that you have not put any effort at all to find an answer yourself.
Cheers!
the v_statement variable you have written won't be validated. If you really want to write a string in this format, then use pipes to append.
I am trying to format some output in Standard ML. I need to display some real values as rounded to a certain decimal place, and I also need to be able to display some real values using scientific notation.
The signature for the print function is
val it = fn : string -> unit
which doesn't seem to allow for the use of formatting codes or any other parameters. I also haven't had any luck finding documentation online. Ideally I was hoping the print function in SML would have similar functionality to printf in C...
Standard ML is a statically-typed language. It's hard to make something like printf in a type-safe way.
The SML Basis Library contains some formatting operations for numbers. But to use them is relatively verbose and relatively difficult to figure out. For example, to format a real number into a string in scientific notation with 3 places after the decimal point, you can do something like this:
Real.fmt (StringCvt.SCI (SOME 3)) 4324423423.5; (* evaluates to string "4.324E9" *)
Ugly, right?
Some implementations offer other formatting methods. For example, SML/NJ has a Format structure that allows you to use a printf-style formatting string. However, the arguments must be wrapped according to their type:
Format.format "%.3e" [Format.REAL 4324423423.5]; (* evaluates to string "4.324e09" *)
Other SML implementations might have their own custom formatting functions.
The WRITE statement has a lot of options, so I was wondering, does it call CONVERSION_EXIT_* functions, or how does it print the primitive data types in so many ways?
And if it does use CONVERSION_EXIT_*s, what are those?
The primitive data types (DATA foo TYPE n LENGTH 10) do not have any conversion exits (ALPHA, etc.) assigned to them.
You can choose them manually, for example with
WRITE ... TO ... USING EDIT MASK '==ALPHA'.
or they can be assigned to a data dictionary domain (transaction code SE11). In this case, they are implicitly called for example:
by the screen (dynpro) processing (unless turned off explicitly).
by WRITE
DATA(langu) = CONV syst-langu( 'E' ). " domain SYLANGU has conv.exit ISOLA
DATA text TYPE c LENGTH 2.
WRITE langu TO text. " conv.exit ISOLA converts 'E' into 'EN'
Except WRITE, ABAP itself does very little to support conversion exits - which is a good thing because the conversion should take place only at the input/output borders of the program and not internally.
It's a good idea to keep all of the data in the internal format as long as you're working on it and only convert it right before the output takes place.
Visual Basic 2010 (Express). I can best give this by example...
If I take a string from a textbox and assign it to an integer variable, I'm under the impression that you're supposed to use CInt to explicitly convert the contents to an integer.
intMyCount = CInt(txtUserInput.Text)
However, if I don't do that, it still seems to work. Similarly, if I have an integer and concatenate it into a label's text property, it still works:
lblResults.Text = intMyCount & " number of times."
rather than using intMyCount.ToString.
Why does it work? Is VB doing implicit conversions when possible? Are there examples where not explicitly converting with .ToString or using CInt would cause unexpected results?
This is done using late-binding, and it's dangerous because if the conversion ever fails (and there's lots of cases where your first example could fail) it ends up in an exception at runtime. To get the compiler to enforce safer casting, turn Option Strict On.
Additionally, most of the time you don't want to use CInt() to convert your string to int. Instead, prefer Integer.Parse() or Integer.TryParse().
Some languages handle string concatenation easily like this for the non-casting to string. Some also handle non-casting to numeric types to do calculations. Some languages don't handle it at all. However as a best-practice, I would always cast the variable to the type you want to avoid issues with improper input types.
In algebra if I make the statement x + y = 3, the variables I used will hold the values either 2 and 1 or 1 and 2. I know that assignment in programming is not the same thing, but I got to wondering. If I wanted to represent the value of, say, a quantumly weird particle, I would want my variable to have two values at the same time and to have it resolve into one or the other later. Or maybe I'm just dreaming?
Is it possible to say something like i = 3 or 2;?
This is one of the features planned for Perl 6 (junctions), with syntax that should look like my $a = 1|2|3;
If ever implemented, it would work intuitively, like $a==1 being true at the same time as $a==2. Also, for example, $a+1 would give you a value of 2|3|4.
This feature is actually available in Perl5 as well through Perl6::Junction and Quantum::Superpositions modules, but without the syntax sugar (through 'functions' all and any).
At least for comparison (b < any(1,2,3)) it was also available in Microsoft Cω experimental language, however it was not documented anywhere (I just tried it when I was looking at Cω and it just worked).
You can't do this with native types, but there's nothing stopping you from creating a variable object (presuming you are using an OO language) which has a range of values or even a probability density function rather than an actual value.
You will also need to define all the mathematical operators between your variables and your variables and native scalars. Same goes for the equality and assignment operators.
numpy arrays do something similar for vectors and matrices.
That's also the kind of thing you can do in Prolog. You define rules that constraint your variables and then let Prolog resolve them ...
It takes some time to get used to it, but it is wonderful for certain problems once you know how to use it ...
Damien Conways Quantum::Superpositions might do what you want,
https://metacpan.org/pod/Quantum::Superpositions
You might need your crack-pipe however.
What you're asking seems to be how to implement a Fuzzy Logic system. These have been around for some time and you can undoubtedly pick up a library for the common programming languages quite easily.
You could use a struct and handle the operations manualy. Otherwise, no a variable only has 1 value at a time.
A variable is nothing more than an address into memory. That means a variable describes exactly one place in memory (length depending on the type). So as long as we have no "quantum memory" (and we dont have it, and it doesnt look like we will have it in near future), the answer is a NO.
If you want to program and to modell this behaviour, your way would be to use a an array (with length equal to the number of max. multiple values). With this comes the increased runtime, hence the computations must be done on each of the values (e.g. x+y, must compute with 2 different values x1+y1, x2+y2, x1+y2 and x2+y1).
In Perl , you can .
If you use Scalar::Util , you can have a var take 2 values . One if it's used in string context , and another if it's used in a numerical context .