OpenEuphoria

2. Re: Requesting help again... as a beginner....

• Posted by jimcbrown (admin) May 23, 2009
• 967 views

atom a 
a = gets(KEYBOARD) 
if a = ODDNUMBER then ... 
puts(1,"\nThat is an odd number.") 
end if 

You can't. Nothing will fit. However, you can do this:

if remainder(a, 2) != 0 then 
puts(1,"\nThat is an odd number.") 
end if 

Since by definition, odd numbers are not divisible by two, and so they will have a remainder.

You have another problem, basically gets(KEYBOARD) does not return a number but it returns a sequence. It returns a string of what the user typed, which can not be used as a number directly.

You probably want to use prompt_number() in get.e instead.

It is always \n and \r, never use /n or /r.

The \ is a backslash, and the / is a forward slash.

Basically, \n is a new line. So if you have a string like "Hello.\nThis is some text.", when you print that string it will show up like this:

Hello. 
This is some text. 

But if you put it into a file, it is turned into "Hello.\r\nThis is some text." as this is the DOS text file format. The DOS text file format is a discussion in and of itself.

Btw, if you did a puts(1, "\r") then that would move the cursor back to the first column but it would stay on the same row, the same line. This might be useful if you wanted to erase a line or overwrite a line with new text.

4. Re: Requesting help again... as a beginner....

• Posted by DerekParnell (admin) May 24, 2009
• 969 views

if remainder(a, 2) != 0 then 
puts(1,"\nThat is an odd number.") 
end if 

if and_bits(a, 1) then ... 

Yes, but needs more explanation for a newcomer.

The remainder() idea just works on the premise that odd numbers always have a remainder of 1 when divided by 2. However, dividing is often slower than most other arithmetic operations.

The bit twiddling idea works by knowing that the way that computers store numbers in memory. All numbers are just a set of bits (ones and zeros). In Euphoria, whole numbers use a set of 31-bits and the number of combinations that these have means that it can easily store all the whole numbers from -1,073,741,824 to +1,073,741,823. However, every odd number always has the 31st bit set to 1 and even numbers always have this set to 0. The and_bits() function does a binary 'and' operation on every bit in the two sets of bits supplied in its parameters. An 'and' operation simply returns 0 if either bit is a zero, and returns a 1 if both bits are 1.

So testing for oddness using and_bits(a, 1) is just this ...

31-bits in 'a' = xxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx 
31-bits in 1   = 000 0000 0000 0000 0000 0000 0000 0000 0001 

Therefore, and_bits(a,1) for odd numbers always returns 1 and 0 for even numbers, and this is a lot faster than doing a division.

As this comes up frequently, I'll add it as a standard function to the math.e library for v4. The inlining feature should ensure that this will not have a function call overhead.

6. Re: Requesting help again... as a beginner....

• Posted by DanM May 24, 2009
• 1009 views
• Last edited May 25, 2009

Which editor?
If it's the Euphoria "ed", then you have to go over to the left top of the cmd window, click on the icon there, select first "edit", then "mark", use the cursor to mark the section you want to copy, then go back to that icon at the top left, select "edit" and then "copy"; that will put the marked portion into the "clipboard",(you have to make sure to go as far to the right side as necessary, to get full extent of all lines), then here in a post just press <ctl>V to put what you copied into a post here.

sequence t 
integer h, e 
t = {1,10000} 
while t = {1,10000} do 
t = prompt_number("\nPlease enter a positive odd number.") 
if t <= 2 then 
puts(1,"\nThat is an unusable number.") 
t = {1,10000} 
else t = and_bits(t,1) 
power(t,2) = h 
____________________ 
puts(1,h) 

power(t,2) = h 

power is a function, not a procedure, your code there needs to be:
h = power(t,2)

I'm not sure if it's adequate to have "h" be an integer, though, because you could be raising decimal fractions to a power, and the result of that won't be integer type. So maybe you need "h" to be atom, I'm not sure.

Dan

8. Re: Requesting help again... as a beginner....

• Posted by Mattymatt May 24, 2009
• 997 views
• Last edited May 25, 2009

Also, i'm doing this in .exw but I think I mentioned that before.

Okay, changed, but it keeps saying true/false condition must be an ATOM. I have changed h and e to atoms though. in the ex.err it says

6 true/false condition must be an ATOM

C:\EUPHORIA\include\get.e: input_file = <no value> input_string = <no value> string_next = <no value> ch = <no value>

t = {1,10000} h = <no value> e = <no value>

I tried adding an atom k = 10000 and using that to make t = {1,k}, and changing t to k, for the prompt number. something like k = prompt_number("\nsomething",t), but that didn't work either, its became basically the same ex.err file, but it would be 7 true/fals condition must be an ATOM, and added k = 10000.

Can anyone help?

10. Re: Requesting help again... as a beginner....

• Posted by Mattymatt May 25, 2009
• 973 views

sequence range 
atom h, e, t 
range = {1,10000} 
t = -1 
while 1 do 
	t = prompt_number("\nPlease enter a positive odd number.", range) 
	if t <= 2 then 
		puts(1,"\nThat is an unusable number.") 
	else 
		t = and_bits(t,1) 
		h = power(t,2) 
		printf(1, "%d\n", {h}) 
	end if 
end while 

You. Rock. The program actually starts! For me, thats a big leap forward. However, there are a few areas that are confusing to me. Why does t = -1 need to be there? I deleted that and it still works. Just so I know, in <eucode> while 1 do </eucode> means 1 means true? Because I changed the number, and that still works.

The only faulty up part is when I put in a number, I always get back a 1 or 0. I want it so I get back the number by the power of 2. 1 means true if I remember, and 0 means false.... but, I was while I was messing with it, I think I got a 0.5 somehow, I don't remember what I put though. Shouldn't printf(1, "%d\n", {h}) show h instead of one, say if I typed in 5, it should return 25? I tried print(), puts(), messed with t = 1 in the beginning, and while.

12. Re: Requesting help again... as a beginner....

• Posted by Mattymatt May 25, 2009
• 993 views

sequence range 
atom h, t 
range = {3,10000} 
 
while 1 do 
    t = prompt_number("\nPlease enter a positive odd number greater than 2: ", range) 
    if not and_bits(t,1) then 
        puts(1,"\nThat is not an  odd number, try again.") 
    else 
        h = power(t,2) 
        printf(1, "%d squared is %d\n", {t,h}) 
    end if 
 
end while 

Thanks, this helps a lot, I think I don't need anymore help, but if I do I'll come back and ask. Thanks everyone!

14. Re: Requesting help again... as a beginner....

• Posted by jimcbrown (admin) May 25, 2009
• 980 views

This is correct.

In short, 0 is false. Any integer or decimal point number that is not zero is true, i.e. -1 and 1 and 9 and 0.1 are all true.

16. Re: Requesting help again... as a beginner....

• Posted by DanM May 25, 2009
• 997 views
• Last edited May 26, 2009

this usage is an optimized form of the the "while some condition true, do the following, but exit when the condition is not true".

It's optimized in that in this form, it doesn't actually (as far as I know) check for any change in the status of the condition, but simply continuously loops. In such a case, you should usually provide some way to actually EXIT the loop, using the command "exit". Perhaps, allow user to input a zero, and if a zero is input, the command in the if statement would be "exit".

Dan

18. Re: Requesting help again... as a beginner....

• Posted by euler May 26, 2009
• 982 views

Firstly, that's not the point, Mattymatt. Everyone here is willing to help, no complaints about asking questions, of any level, but you'd help us a lot (and also yourself) if you elaborate it a bit. Secondly, several fellows asked you simple questions and you answered to none. I find this sort of impolite. They are trying to refine which is the best answer, or just trying to find your needs, so you could at least answer their questions.

Again, this is a very helpful bunch of people. I'm here also to learn so, let's not spoil the help offered so kindly. My tuppence.

20. Re: Requesting help again... as a beginner....

• Posted by Mattymatt Jun 04, 2009
• 930 views

sequence range 
atom h, t 
range = {3,10000} 
 
while 1 do 
    t = prompt_number("\nPlease enter a positive odd number greater than 2: ", range) 
    if not and_bits(t,1) then 
        puts(1,"\nThat is not an  odd number, try again.") 
    else 
        h = power(t,2) 
        printf(1, "%d squared is %d\n", {t,h}) 
    end if 
 
end while 

Yes, that is what I was trying to do, then later I was going to add a formula to get another number. Just didn't want you guys to write the exact code, because then I would have done none of the work.

22. Re: Requesting help again... as a beginner....

• Posted by Dan_M Jun 04, 2009
• 927 views
• Last edited Jun 05, 2009

HUH? [insert confused face here]

Dan