Best Database Format for Scientific Data? 
Author Message
 Best Database Format for Scientific Data?

I have been using VXbase (i.e. dbase and clipper indexes) with my scientific
data.  I have tried to update with ROCK-E-T by SuccessWare but have
encountered a major limitation.

When dealing with scientific data, results are often reported with varying
precision depending on the source.  For example I may need to store values
such as 56.12 57.345 and 58 in the same data field.  The problem is that
ROCK-E-T automatically rounds the values to the precision of the dbase field
when the data are stored, so for a numeric field of precision 3 the data would
be stored as 56.120 57.345 and 58.000.  They have suggested that I store
my data as character and then convert it to numeric.  This of course
creates problems when accessing data from other programs.
I need to find a database (format, engine, add-on what ever) that will
allow me to define a numeric field with the maximum expected precision
and store the data with the correct precision without a forced
rounding.

Any suggestions?  I am prepared to abandon the xbase format to solve
my problem.
Would Access do?

Thanks
Linda Richard



Tue, 27 Oct 1998 03:00:00 GMT  
 Best Database Format for Scientific Data?

Quote:

>I have been using VXbase (i.e. dbase and clipper indexes) with my scientific
>data.  I have tried to update with ROCK-E-T by SuccessWare but have
>encountered a major limitation.

>When dealing with scientific data, results are often reported with varying
>precision depending on the source.  For example I may need to store values
>such as 56.12 57.345 and 58 in the same data field.  The problem is that
>ROCK-E-T automatically rounds the values to the precision of the dbase field
>when the data are stored, so for a numeric field of precision 3 the data would
>be stored as 56.120 57.345 and 58.000.  They have suggested that I store
>my data as character and then convert it to numeric.  This of course
>creates problems when accessing data from other programs.
>I need to find a database (format, engine, add-on what ever) that will
>allow me to define a numeric field with the maximum expected precision
>and store the data with the correct precision without a forced
>rounding.

>Any suggestions?  I am prepared to abandon the xbase format to solve
>my problem.
>Would Access do?

>Thanks
>Linda Richard

Access will not let you do what you want directly. I know of
no database that allows you to store both value and format
in one field. In Access, you could store the value in a single
or double precision floating point field, and the format,
either in a basic format string ("000.000") or as a fortran like
code ("F3.3"). Then write VB code (or Access code) to do the
translation. Although I'm not familiar with ROCKET, seems you
you should be able to do something similar.

Herb Schaake



Tue, 27 Oct 1998 03:00:00 GMT  
 Best Database Format for Scientific Data?

Quote:


>>I have been using VXbase (i.e. dbase and clipper indexes) with my scientific
>>data.  I have tried to update with ROCK-E-T by SuccessWare but have
>>encountered a major limitation.

>>When dealing with scientific data, results are often reported with varying
>>precision depending on the source.  For example I may need to store values
>>such as 56.12 57.345 and 58 in the same data field.  The problem is that
>>ROCK-E-T automatically rounds the values to the precision of the dbase field
>>when the data are stored, so for a numeric field of precision 3 the data would
>>be stored as 56.120 57.345 and 58.000.  They have suggested that I store
>>my data as character and then convert it to numeric.  This of course
>>creates problems when accessing data from other programs.
>>I need to find a database (format, engine, add-on what ever) that will
>>allow me to define a numeric field with the maximum expected precision
>>and store the data with the correct precision without a forced
>>rounding.

>>Any suggestions?  I am prepared to abandon the xbase format to solve
>>my problem.
>>Would Access do?

>>Thanks
>>Linda Richard

>Access will not let you do what you want directly. I know of
>no database that allows you to store both value and format
>in one field. In Access, you could store the value in a single
>or double precision floating point field, and the format,
>either in a basic format string ("000.000") or as a Fortran like
>code ("F3.3"). Then write VB code (or Access code) to do the
>translation. Although I'm not familiar with ROCKET, seems you
>you should be able to do something similar.
>Herb Schaake

The only alternative would be to split the number.
Store the integer value in 1 field, the decimal value
in another. Which you could do with a simple
mod statement.  From the sound of it, however,
you may not want that.

I know of no standard database file scheme that
allows what you are looking for.

http://www.xnet.com/~kd9fb



Wed, 28 Oct 1998 03:00:00 GMT  
 Best Database Format for Scientific Data?


writes:

Quote:
>I have been using VXbase (i.e. dbase and clipper indexes) with my
scientific
>data.  I have tried to update with ROCK-E-T by SuccessWare but have
>encountered a major limitation.

>When dealing with scientific data, results are often reported with
varying
>precision depending on the source.  For example I may need to store
values
>such as 56.12 57.345 and 58 in the same data field.  The problem is that
>ROCK-E-T automatically rounds the values to the precision of the dbase
field
>when the data are stored, so for a numeric field of precision 3 the data
>would
>be stored as 56.120 57.345 and 58.000.  They have suggested that I store
>my data as character and then convert it to numeric.  This of course
>creates problems when accessing data from other programs.
>I need to find a database (format, engine, add-on what ever) that will
>allow me to define a numeric field with the maximum expected precision
>and store the data with the correct precision without a forced
>rounding.

>Any suggestions?  I am prepared to abandon the xbase format to solve
>my problem.
>Would Access do?

>Thanks
>Linda Richard

I'm not quite sure whether I understood it right:

You simply want to store a number as is, i.e. no rounding etc. wanted.
Each stored value can have a different precision.
Later you want to work on those numbers, possibly using different formats
and different precision for display.
With ROCK-E-T you cannot retrieve the original value, because it has been
rounded before storing.

If it is this what you want, then you could store your data in
Access-fields with datatype Double (10 decimal places, range from
-1.797693...E308 to +1.797693...E308, takes 8 bytes per value).
If you need less precision or value range, you could use the Single
datatype (6 decimal places, range from -3.402...E38 to +3.402...E38, uses
4 bytes per value).
The values are stored as they are.
If you need to know the _original_ precision, you'll have to store it
perhaps in an additional field (datatype Byte, range from 0 to 255).
Your above example would look like this:

Field A, Double    Field B, Byte

56.12                  2
57.345                3
58                       0

Please let me know whether that helped.

So long

Thomas

*****
If you are well, don't worry ... it will pass over.
*****



Fri, 30 Oct 1998 03:00:00 GMT  
 Best Database Format for Scientific Data?


Quote:
: writes:

: >When dealing with scientific data, results are often reported with
: varying
: >precision depending on the source.  For example I may need to store
: values

: The values are stored as they are.
: If you need to know the _original_ precision, you'll have to store it
: perhaps in an additional field (datatype Byte, range from 0 to 255).
: Your above example would look like this:
: Field A, Double    Field B, Byte
: 56.12                  2
: 57.345                3
: 58                       0

You are on the right track. Store the number as a double or single in
one column, store the number of _significant figures_ in another column.

Jim



Sat, 31 Oct 1998 03:00:00 GMT  
 
 [ 5 post ] 

 Relevant Pages 

1. Scientific format #'s

2. DLL that can generate scientific plot in GIF format

3. Scientific Number Format

4. scientific format specifier

5. Basic Program For Processing Scientific Data

6. Data collection from a scientific instrument

7. Data Control/database object which is better ?

8. Best way to write data to database?

9. Best method for remote data of Oracle database

10. Read HTML formatted data from database field, Insert Wordmerge fields, and save as Word document

11. data Control: unrecognized Database Format

12. Data Form Wizard : Unrecoginzed Database Format

 

 
Powered by phpBB® Forum Software