Summing array elements
in [Fortran]
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From: Richard Maine on 20 Apr 2008 00:29 dongyuanxun <dongyuanxun(a)gmail.com> wrote: > On Apr 20, 12:12 pm, "Gerry Ford" <ge...(a)nowhere.ford> wrote: > > real(dim =50):: a > That looks that your Compiler doesn't support the dim sign. Try > "real :: a(50)",please. Nor would I expect any compiler to support it. 1. It is spelled dimension rather than dim. (This isn't basic) 2. There are quite a large number of places where one can specify dimension, but in parens after a type name is not one of them. That would be a type parameter. The real type does not have a type parameter named dim (or dimension either). Its only type parameter is named kind. -- Richard Maine | Good judgement comes from experience; email: last name at domain . net | experience comes from bad judgement. domain: summertriangle | -- Mark Twain
From: dongyuanxun on 20 Apr 2008 00:37 On Apr 20, 12:29 pm, nos...(a)see.signature (Richard Maine) wrote: > dongyuanxun <dongyuan...(a)gmail.com> wrote: > > On Apr 20, 12:12 pm, "Gerry Ford" <ge...(a)nowhere.ford> wrote: > > > real(dim =50):: a > > That looks that your Compiler doesn't support the dim sign. Try > > "real :: a(50)",please. > > Nor would I expect any compiler to support it. > > 1. It is spelled dimension rather than dim. (This isn't basic) > > 2. There are quite a large number of places where one can specify > dimension, but in parens after a type name is not one of them. That > would be a type parameter. The real type does not have a type parameter > named dim (or dimension either). Its only type parameter is named kind. > > -- > Richard Maine | Good judgement comes from experience; > email: last name at domain . net | experience comes from bad judgement. > domain: summertriangle | -- Mark Twain That's Right. We can write like this "real,DIMENSION(50) :: a".
From: Gerry Ford on 20 Apr 2008 02:29 "Richard Maine" <nospam(a)see.signature> wrote in message news:1ifny75.cq0wgnblsypaN%nospam(a)see.signature... > dongyuanxun <dongyuanxun(a)gmail.com> wrote: > >> On Apr 20, 12:12 pm, "Gerry Ford" <ge...(a)nowhere.ford> wrote: > >> > real(dim =50):: a > >> That looks that your Compiler doesn't support the dim sign. Try >> "real :: a(50)",please. > > Nor would I expect any compiler to support it. > > 1. It is spelled dimension rather than dim. (This isn't basic) > > 2. There are quite a large number of places where one can specify > dimension, but in parens after a type name is not one of them. That > would be a type parameter. The real type does not have a type parameter > named dim (or dimension either). Its only type parameter is named kind. Thanks, Xuan and Richard. I must have been thinking of MM's scatter, where the dim=1 in the minloc statement is more of a qualifier. real :: a(50) do 23 j=1, 50 a(j) = 1.0 * j 23 continue s=0. do 1 i=5,50 s=s+a(i) 1 continue print *, s end I know we're not supposed to solve homework, but sometimes I behave more like I wish others had when I was in school. -- "A belief in a supernatural source of evil is not necessary; men alone are quite capable of every wickedness." ~~ Joseph Conrad (1857-1924), novelist
From: Luka Djigas on 20 Apr 2008 10:07 On Sat, 19 Apr 2008 20:40:11 -0500, "Craig Dedo" <cdedo(a)wi.rr.com> wrote: > This most likely is a homework assignment. However, if I am mistaken and >Luka is new to Fortran . . . Nope, not homework assignment. Well, it's work, and I'm doing it at home, but I don't think that counts ... > > There is always the SUM() intrinsic function. It can sum an array along any >dimension or the whole array and can even sum those array elements for which the >value of a corresponding MASK array is true. RTFM. I know about the sum intristic. Never used it though. I don't like using intristics where I can do it by plain loop or something (ok, I don't do the sinus function that way) ... that way I don't have to think when I'm reading the code next time, what exactly does the specified intristic do. Anyway, I read the help. But didn't manage to figure it out. As far as I can see, sum can be used to summ an entire array in one or more dimensions. How can one sum just some elements from, for example one dimensional array ? regards Luka
From: Luka Djigas on 20 Apr 2008 10:30
On Sat, 19 Apr 2008 21:10:10 -0700 (PDT), dongyuanxun <dongyuanxun(a)gmail.com> wrote: > You can also prepare a function called sum(),if your IDE doesn't >support the sum() intrinsic function. Uhmm, I don't think that IDE has much to do with it. You probably ment the compiler. About the function. That is always the possibility. Unfortunately (unfortunately? :-) my compiler (cvf66c) does support the sum intristic, but looks like I understood it's capabilities the wrong way. I didn't understood the mask option. As far as I have gone with the sum intristic is that it can summ all elements in specified dimensions of an array. I didn't understand (no examples in help either) how can one sum just some elements from an array ... regards Luka p.s. I know this is a little dumb question for some people here. But I'm a self learned fortran user, learned what i know through reading old manuals and by figuring out someone else's code. So far I always found it better just to ask, what seems a dumb question, and to bear critics for a while, but to get some idea from other people's answers, than to keep on doing something in a way which is, for one reason or another, wrong. |