1. Sequence trouble
Hi to all.
Recently, I was working on a shape loader/writer/scanner and others "er",
but something is not quite right.
Sometime past, I did some sequence tests, and I found that if I declare a
sequence, and put each value, like sequence[1]=xxx, sequence[2]=aaa, ex.err
returned that the sequence value was zero!!
Someone can explain it to me? I really need help!!
Eduardo Uemura Okada
e-mail: cool at art.com.br
2. Sequence trouble
Eumura, you wrote:
> Sometime past, I did some sequence tests, and I found that if I declare a
>sequence, and put each value, like sequence[1]=xxx, sequence[2]=aaa, ex.err
>returned that the sequence value was zero!!
I'm not exactly clear on the situation you are describing, but if you are
doing this . . .
sequence s
s[1] = 5
s[2] = 4
. . . then you will definitely get an error because the sequence has
not been initialized, only declared, and so it does not actually *have*
element 1, 2, etc. yet.
That shouldn't give an error return of s = 0, but it will say this (in
ex.err):
s = <no value>
Craig
3. Sequence trouble
Hey Craig (Gilbert) and anyone, what I mean is:
sequence data
data[1]=12
data[2]=23
data[3]=54
data=append(data,{data[1],data[2],data[3]})
ex.err results: data=<no value>
That's just an example, but my real situation is a sequence in what each
element is a sequence of 3 numbers, just like
{{1,2,3},{4,5,6},{7,8,9},{.,.,.},...}.
Anyone have a solution to put the values in the sequence without return
<no value> ?
I'll be thankful
Eduardo Uemura Okada
e-mail: cool at art.com.br
4. Re: Sequence trouble
Eduardo Uemura Okada <cool at ART.COM.BR> wrote:
> Hey Craig (Gilbert) and anyone, what I mean is:
>
> sequence data
> data[1]=12
> data[2]=23
> data[3]=54
> data=append(data,{data[1],data[2],data[3]})
>
> ex.err results: data=<no value>
>
> That's just an example, but my real situation is a sequence in what each
> element is a sequence of 3 numbers, just like
> {{1,2,3},{4,5,6},{7,8,9},{.,.,.},...}.
> Anyone have a solution to put the values in the sequence without return
> <no value> ?
> I'll be thankful
Craig's reply to your first message was correct. Once you declare a
sequence, you CANNOT refer to it using a subscript unless you first
give it some subscripts. What I mean is that for the following code,
you cannot assign a value to x[i]:
sequence x
x[1] = 5
x[10] = 50
Both x[1] and x[10] will crash the program because x does not yet
have a subscript value of 1 or 10. Instead, you must put your data
into x directly (not referring to it with subscripts) or initialize x
using the repeat() function. For example:
sequence x
x = {5,0,0,0,0,0,0,0,0,50}
AND
sequence x
x = repeat(0, 10)
x[1] = 5
x[10] = 50
Will both result in a sequence where x = {5,0,0,0,0,0,0,0,0,50} that
can now be referred to using a subscript [i] where 1<=i<=10. I hope
this helps. Maybe someone else can give a clearer answer than this
if it hasn't.
James Powell
5. Re: Sequence trouble
Eduardo wrote:
>sequence data
>data[1] = 12
>data[2] = 23
>data[3] = 54
>data = append(data,{data[1],data[2],data[3]})
> . . .(SKIPPED) . . .my real situation is a sequence in what each
>element is a sequence of 3 numbers, just like
>{{1,2,3},{4,5,6},{7,8,9},{.,.,.},...}.
Looks to me like you still have the problem of not initializing the
data var.
Try this:
sequence data
data = {} -- initialize it!
data = append( data, {1,2,3} )
data = append( data, {4,5,6} )
-- etc., data should now be { {1,2,3}, {4,5,6} }
Craig
6. Re: Sequence trouble
> sequence data
> data[1]=12
> data[2]=23
> data[3]=54
> data=append(data,{data[1],data[2],data[3]})
>
> ex.err results: data=<no value>
Hi Eduardo,
Maybe you write wrong the code in your mail, but maybe the bug is
that you declared the sequence "sequence data" and then just started
doing "data[x]=y" wich is WRONG. You must first give a value to
"data" so Euphoria knows it's shape.. just after declaration, "data"
is an empty sequence "{}". You code should look like this:
sequence data
data = {12,23,54}
data=append(data,{data[1],data[2],data[3]})
Now data should be:
{12,23,54,{12,23,54}}
Other way could be:
sequence data
data = repeat({},3) --Replace "3" with the length you want
data[1]=12
data[2]=23
data[3]=54
...
If you want to make a sequence of sequences ("{{1,1,1},{1,1,1}....}")
then use something like:
sequence data
data=repeat(repeat({},3),10)
data[1][1]=xxx
data[1][2]=xxx
data[1][3]=xxx
....
data[10][3]=xxx
This creates a sequence ("data") of length 10, and each of this
elements is a sequence itself of length 3.
Hope this helps...
Regards,
Daniel Berstein
danielberstein at usa.net
http://www.geocities.com/SiliconValley/Heights/9316
