# Re: convert a decimal to 32 bit unsigned binary

From: cheryl Ma <xiaoyancloud_at_nyahnyahspammersnyahnyah>
Date: Wed Feb 20 2013 - 14:08:22 MST

Thank you very much!

On Wed, Feb 20, 2013 at 3:55 PM, David Brown <dbrown@ucar.edu> wrote:

> a = str_index_of_substr(str2,"1",0)
> print(dimsizes(a))
>
> (a will be an array containing the index of each "1" character; the size
> of the array is how many "1"s there are.
> -dave
>
> On Feb 20, 2013, at 1:45 PM, cheryl Ma wrote:
>
> One more question: Now suppose I have str2
> =00100100000000000000000000000000,
>
> using ncl, how to count how many days having the observations (1 means
> having observations, 0 means no)?
>
> Thanks,
> Xiaoyan
>
>
>
> On Tue, Feb 19, 2013 at 1:52 PM, Dave Allured - NOAA Affiliate <
> dave.allured@noaa.gov> wrote:
>
>> Xiaoyan,
>>
>> Okay, here is an NCL program that converts FROM a 32-bit unsigned
>> integer, TO a character string of length 32. The output should be
>> equivalent to the Fortran program.
>>
>> begin
>> i = 36I ; start with 32-bit unsigned integer
>> nbits = 32 ; number of bits to display
>>
>> print ("i = " + i + " (NCL type = " + typeof (i) + ")")
>>
>> str1 = ""
>> str2 = ""
>> ic = i
>>
>> do n = 1, nbits
>> bit = (ic % 2) ; pick off the lowest bit
>> ic = ic / 2 ; shift right one bit, drop lowest
>> str1 = bit + str1
>> str2 = str2 + bit
>> end do
>>
>> print ("MSB first: " + str1)
>> print ("LSB first: " + str2)
>> end
>>
>> Output:
>> (0) i = 36 (NCL type = uint)
>> (0) MSB first: 00000000000000000000000000100100
>> (0) LSB first: 00100100000000000000000000000000
>>
>> --Dave
>> Please reply to list only!
>>
>> On Tue, Feb 19, 2013 at 10:27 AM, cheryl Ma <xiaoyancloud@gmail.com>wrote:
>>
>>> Thanks, Dave.
>>>
>>> Below is a fortran code which is provided by Andrew Mai (Thanks Andrew
>>> !). cv in the code is what I want.
>>>
>>> program dumpbits
>>> implicit none
>>>
>>> integer :: i,ic,icv
>>> character(len=32) :: c,cv
>>>
>>> i = 36
>>> print '(b32.32)',i
>>>
>>> write(c,'(b32.32)') i
>>>
>>> do ic=1,32
>>> icv=33-ic
>>> cv(icv:icv)=c(ic:ic)
>>> enddo
>>>
>>> print '(a32)',cv
>>>
>>> end
>>>
>>>
>>>
>>> On Tue, Feb 19, 2013 at 11:54 AM, Dave Allured - NOAA Affiliate <
>>> dave.allured@noaa.gov> wrote:
>>>
>>>> Xiaoyan,
>>>>
>>>> Oops, my mistake. I thought that the digits of "36" meant day numbers
>>>> 3 and 6. By coincidence, it really is the encoded value of the 3rd and 6th
>>>> bits, in other words 36 = 2^(3-1) + 2^(6-1). Sorry for the confusion.
>>>>
>>>> Returning to your original question, use the NCL function "touint" to
>>>> convert other NCL data types (numbers and strings) to NCL 32-bit unsigned
>>>> binary. The following example converts "36" as an NCL string type to data
>>>> type "uint" which is NCL 32-bit unsigned binary. Is this what you are
>>>> looking for?
>>>>
>>>> x = "36" ; NCL string type
>>>> y = touint (x)
>>>> print (y)
>>>>
>>>> Output:
>>>> Variable: y
>>>> Type: uint
>>>> Total Size: 4 bytes
>>>> 1 values
>>>> Number of Dimensions: 1
>>>> Dimensions and sizes: [1]
>>>> Coordinates:
>>>> (0) 36
>>>>
>>>> "uint" and other NCL data types are explained on this page:
>>>> http://www.ncl.ucar.edu/Document/Manuals/Ref_Manual/NclDataTypes.shtml
>>>>
>>>> If this is not what you want, it might be helpful if you show us the
>>>> Fortran code that you mentioned, so that we can understand what data
>>>> structure you are trying to get.
>>>>
>>>> --Dave
>>>> Please reply to list only!
>>>>
>>>> On Tue, Feb 19, 2013 at 7:26 AM, cheryl Ma <xiaoyancloud@gmail.com>wrote:
>>>>
>>>>> Dave,
>>>>>
>>>>> in this case, "36" is a decimal number. It need be converted to a
>>>>> 32-bit binary number and then one can know which day having the
>>>>> observation, e.g. If there is observation on the 1st day of the month, then
>>>>> bit 1 would be set to true and if there is observation on the 2nd day of
>>>>> the month, then bit 2 would be set to true and so on.
>>>>>
>>>>> We can write a fortran code to convert a decimal number to a 32-bit
>>>>> binary number. My question is if there is a function in ncl to do this?
>>>>>
>>>>> Thanks,
>>>>> Xiaoyan
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> On Mon, Feb 18, 2013 at 4:01 PM, Dave Allured - NOAA Affiliate <
>>>>> dave.allured@noaa.gov> wrote:
>>>>>
>>>>>> Xiaoyan,
>>>>>>
>>>>>> Be careful. In the example you show, "36" is NOT a decimal number.
>>>>>> It looks like it is really a list of two separate integers, 3 and 6.
>>>>>>
>>>>>> It is good that the example image showed the graphic mapping between
>>>>>> calendar days and bit positions, because the statement "Days of Month
>>>>>> Observed = 36" is badly constructed and very misleading. Maybe they should
>>>>>> have said "Days of Month Observed = 3 and 6".
>>>>>>
>>>>>> So, what do you really want to do? Maybe convert a LIST of calendar
>>>>>> day numbers 1 to 31, to a 32-bit unsigned integer, using bit position
>>>>>> encoding as shown in this example?
>>>>>>
>>>>>> Please reply only to the user list!
>>>>>>
>>>>>> --Dave
>>>>>>
>>>>>> On Mon, Feb 18, 2013 at 8:57 AM, cheryl Ma <xiaoyancloud@gmail.com>wrote:
>>>>>>
>>>>>>> Dear all,
>>>>>>>
>>>>>>> Is there any function in NCL to convert a decimal number to a 32-bit
>>>>>>> unsigned binary? In an example shown below, 36 is a decimal, so its binary
>>>>>>> is 00100100000000000000000000000000.
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Xiaoyan
>>>>>>>
>>>>>>> ==============================================
>>>>>>> [image: Figure 3: days of month flag interpretation.]
>>>>>>>
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>>>>>>
>>>>>
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>>>
>>
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Received on Wed Feb 20 14:08:48 2013

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