ver. 17 problem reading in decimals

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ver. 17 problem reading in decimals

Roberts, Michael

Good Morning Listers,

 

Have a condition not encountered before, and wonder if anyone else has – my data, a tab delimited text file has several numeric fields with about 12 decimals.  When reading in these data if I set the decimals value (Fx.x) to over 7 I get errors.  Setting the value to 7 or less works.  Is this a glitch or intentional, and if intentional, how can I get around it?

 

TIA

 

Mike

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Re: ver. 17 problem reading in decimals

Oliver, Richard

What kind of errors? What does the syntax look like? I can read a tab-delimited file that contains values with 12 decimals without any problems.

 


From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Roberts, Michael
Sent: Thursday, May 21, 2009 10:37 AM
To: [hidden email]
Subject: ver. 17 problem reading in decimals

 

Good Morning Listers,

 

Have a condition not encountered before, and wonder if anyone else has – my data, a tab delimited text file has several numeric fields with about 12 decimals.  When reading in these data if I set the decimals value (Fx.x) to over 7 I get errors.  Setting the value to 7 or less works.  Is this a glitch or intentional, and if intentional, how can I get around it?

 

TIA

 

Mike

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Re: ver. 17 problem reading in decimals

Roberts, Michael

Hi Richard,

 

I have run a few tests varying the number of decimals and the following is what seems to be the case:

 

Up to 16 decimals there are no problems; I varied the decimals from F20.19 through F20.15, and at F20.16 there were no errors.  Syntax is generated by the dialogue box (wanted to see what SPSS was seeing) – the bit with the relevant variables is included:

“...

GET DATA

  /TYPE=TXT

  /FILE='<<filepath>>’

  /DELCASE=LINE

  /DELIMITERS=","

  /ARRANGEMENT=DELIMITED

  /FIRSTCASE=2

  /IMPORTCASE=FIRST 9000

  /VARIABLES=

.

.

.

  on_risk A1

  demoscore F21.19

  demofact F1.0

  rxscore F20.17

  rxfact F1.0

  totscore F21.19

  adjscore F21.19

CACHE.

EXECUTE.

DATASET NAME DataSet3 WINDOW=FRONT.

 

The error I get when running the code as is –

Error.  Command name: GET DATA

(2265) Unrecognized or invalid variable definition.

This command not executed.

CACHE.

EXECUTE.

 

Error # 105.  Command name: EXECUTE

This command is not valid before a working file has been defined.

This command not executed.

DATASET NAME DataSet3 WINDOW=FRONT.”

 

When changing the decimal value to 16 (F21.16), the file reads in OK.  Is this a documented limitation of the decimals, or just a bug?

 

TIA

 

Mike

 

 

From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Oliver, Richard
Sent: Thursday, May 21, 2009 12:54 PM
To: [hidden email]
Subject: Re: ver. 17 problem reading in decimals

 

What kind of errors? What does the syntax look like? I can read a tab-delimited file that contains values with 12 decimals without any problems.

 


From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Roberts, Michael
Sent: Thursday, May 21, 2009 10:37 AM
To: [hidden email]
Subject: ver. 17 problem reading in decimals

 

Good Morning Listers,

 

Have a condition not encountered before, and wonder if anyone else has – my data, a tab delimited text file has several numeric fields with about 12 decimals.  When reading in these data if I set the decimals value (Fx.x) to over 7 I get errors.  Setting the value to 7 or less works.  Is this a glitch or intentional, and if intentional, how can I get around it?

 

TIA

 

Mike

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Re: ver. 17 problem reading in decimals

Oliver, Richard

Right. There was a known issue with the Text Wizard, which I think has been resolved for the next release. You cannot specify a format value that contains more than 16 decimal positions, but the Text Wizard was attempting to do so. Keep in mind that double-precision floating point values are basically limited to 16 digits of precision. So if you really have 21-digit values with 19 decimals, these values cannot be represented precisely in SPSS (except as strings).

 

All the folks out there who actually know something about computers will correct me if I’m wrong.

 


From: Roberts, Michael [mailto:[hidden email]]
Sent: Thursday, May 21, 2009 2:04 PM
To: Oliver, Richard; [hidden email]
Subject: RE: Re: ver. 17 problem reading in decimals

 

Hi Richard,

 

I have run a few tests varying the number of decimals and the following is what seems to be the case:

 

Up to 16 decimals there are no problems; I varied the decimals from F20.19 through F20.15, and at F20.16 there were no errors.  Syntax is generated by the dialogue box (wanted to see what SPSS was seeing) – the bit with the relevant variables is included:

“...

GET DATA

  /TYPE=TXT

  /FILE='<<filepath>>’

  /DELCASE=LINE

  /DELIMITERS=","

  /ARRANGEMENT=DELIMITED

  /FIRSTCASE=2

  /IMPORTCASE=FIRST 9000

  /VARIABLES=

.

.

.

  on_risk A1

  demoscore F21.19

  demofact F1.0

  rxscore F20.17

  rxfact F1.0

  totscore F21.19

  adjscore F21.19

CACHE.

EXECUTE.

DATASET NAME DataSet3 WINDOW=FRONT.

 

The error I get when running the code as is –

Error.  Command name: GET DATA

(2265) Unrecognized or invalid variable definition.

This command not executed.

CACHE.

EXECUTE.

 

Error # 105.  Command name: EXECUTE

This command is not valid before a working file has been defined.

This command not executed.

DATASET NAME DataSet3 WINDOW=FRONT.”

 

When changing the decimal value to 16 (F21.16), the file reads in OK.  Is this a documented limitation of the decimals, or just a bug?

 

TIA

 

Mike

 

 

From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Oliver, Richard
Sent: Thursday, May 21, 2009 12:54 PM
To: [hidden email]
Subject: Re: ver. 17 problem reading in decimals

 

What kind of errors? What does the syntax look like? I can read a tab-delimited file that contains values with 12 decimals without any problems.

 


From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Roberts, Michael
Sent: Thursday, May 21, 2009 10:37 AM
To: [hidden email]
Subject: ver. 17 problem reading in decimals

 

Good Morning Listers,

 

Have a condition not encountered before, and wonder if anyone else has – my data, a tab delimited text file has several numeric fields with about 12 decimals.  When reading in these data if I set the decimals value (Fx.x) to over 7 I get errors.  Setting the value to 7 or less works.  Is this a glitch or intentional, and if intentional, how can I get around it?

 

TIA

 

Mike

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Re: ver. 17 problem reading in decimals

Roberts, Michael

Richard,

 

Thank you for your help with this.  Do you know whether SAS would be subject to a similar limitation?  The problem was originally discovered with that app.

 

Sincerely

Mike 

 

From: Oliver, Richard [mailto:[hidden email]]
Sent: Thursday, May 21, 2009 3:29 PM
To: Roberts, Michael; [hidden email]
Subject: RE: Re: ver. 17 problem reading in decimals

 

Right. There was a known issue with the Text Wizard, which I think has been resolved for the next release. You cannot specify a format value that contains more than 16 decimal positions, but the Text Wizard was attempting to do so. Keep in mind that double-precision floating point values are basically limited to 16 digits of precision. So if you really have 21-digit values with 19 decimals, these values cannot be represented precisely in SPSS (except as strings).

 

All the folks out there who actually know something about computers will correct me if I’m wrong.

 


From: Roberts, Michael [mailto:[hidden email]]
Sent: Thursday, May 21, 2009 2:04 PM
To: Oliver, Richard; [hidden email]
Subject: RE: Re: ver. 17 problem reading in decimals

 

Hi Richard,

 

I have run a few tests varying the number of decimals and the following is what seems to be the case:

 

Up to 16 decimals there are no problems; I varied the decimals from F20.19 through F20.15, and at F20.16 there were no errors.  Syntax is generated by the dialogue box (wanted to see what SPSS was seeing) – the bit with the relevant variables is included:

“...

GET DATA

  /TYPE=TXT

  /FILE='<<filepath>>’

  /DELCASE=LINE

  /DELIMITERS=","

  /ARRANGEMENT=DELIMITED

  /FIRSTCASE=2

  /IMPORTCASE=FIRST 9000

  /VARIABLES=

.

.

.

  on_risk A1

  demoscore F21.19

  demofact F1.0

  rxscore F20.17

  rxfact F1.0

  totscore F21.19

  adjscore F21.19

CACHE.

EXECUTE.

DATASET NAME DataSet3 WINDOW=FRONT.

 

The error I get when running the code as is –

Error.  Command name: GET DATA

(2265) Unrecognized or invalid variable definition.

This command not executed.

CACHE.

EXECUTE.

 

Error # 105.  Command name: EXECUTE

This command is not valid before a working file has been defined.

This command not executed.

DATASET NAME DataSet3 WINDOW=FRONT.”

 

When changing the decimal value to 16 (F21.16), the file reads in OK.  Is this a documented limitation of the decimals, or just a bug?

 

TIA

 

Mike

 

 

From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Oliver, Richard
Sent: Thursday, May 21, 2009 12:54 PM
To: [hidden email]
Subject: Re: ver. 17 problem reading in decimals

 

What kind of errors? What does the syntax look like? I can read a tab-delimited file that contains values with 12 decimals without any problems.

 


From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Roberts, Michael
Sent: Thursday, May 21, 2009 10:37 AM
To: [hidden email]
Subject: ver. 17 problem reading in decimals

 

Good Morning Listers,

 

Have a condition not encountered before, and wonder if anyone else has – my data, a tab delimited text file has several numeric fields with about 12 decimals.  When reading in these data if I set the decimals value (Fx.x) to over 7 I get errors.  Setting the value to 7 or less works.  Is this a glitch or intentional, and if intentional, how can I get around it?

 

TIA

 

Mike

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Re: ver. 17 problem reading in decimals

Roberts, Michael
In reply to this post by Oliver, Richard

Richard,

 

One more question – my original uncompressed text file was about 5gb.  After I saved it as a .SAV file it grew to 10gb.  Is this normal?

 

Thanking You

Sincerely

 

Mike

 

From: Oliver, Richard [mailto:[hidden email]]
Sent: Thursday, May 21, 2009 3:29 PM
To: Roberts, Michael; [hidden email]
Subject: RE: Re: ver. 17 problem reading in decimals

 

Right. There was a known issue with the Text Wizard, which I think has been resolved for the next release. You cannot specify a format value that contains more than 16 decimal positions, but the Text Wizard was attempting to do so. Keep in mind that double-precision floating point values are basically limited to 16 digits of precision. So if you really have 21-digit values with 19 decimals, these values cannot be represented precisely in SPSS (except as strings).

 

All the folks out there who actually know something about computers will correct me if I’m wrong.

 


From: Roberts, Michael [mailto:[hidden email]]
Sent: Thursday, May 21, 2009 2:04 PM
To: Oliver, Richard; [hidden email]
Subject: RE: Re: ver. 17 problem reading in decimals

 

Hi Richard,

 

I have run a few tests varying the number of decimals and the following is what seems to be the case:

 

Up to 16 decimals there are no problems; I varied the decimals from F20.19 through F20.15, and at F20.16 there were no errors.  Syntax is generated by the dialogue box (wanted to see what SPSS was seeing) – the bit with the relevant variables is included:

“...

GET DATA

  /TYPE=TXT

  /FILE='<<filepath>>’

  /DELCASE=LINE

  /DELIMITERS=","

  /ARRANGEMENT=DELIMITED

  /FIRSTCASE=2

  /IMPORTCASE=FIRST 9000

  /VARIABLES=

.

.

.

  on_risk A1

  demoscore F21.19

  demofact F1.0

  rxscore F20.17

  rxfact F1.0

  totscore F21.19

  adjscore F21.19

CACHE.

EXECUTE.

DATASET NAME DataSet3 WINDOW=FRONT.

 

The error I get when running the code as is –

Error.  Command name: GET DATA

(2265) Unrecognized or invalid variable definition.

This command not executed.

CACHE.

EXECUTE.

 

Error # 105.  Command name: EXECUTE

This command is not valid before a working file has been defined.

This command not executed.

DATASET NAME DataSet3 WINDOW=FRONT.”

 

When changing the decimal value to 16 (F21.16), the file reads in OK.  Is this a documented limitation of the decimals, or just a bug?

 

TIA

 

Mike

 

 

From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Oliver, Richard
Sent: Thursday, May 21, 2009 12:54 PM
To: [hidden email]
Subject: Re: ver. 17 problem reading in decimals

 

What kind of errors? What does the syntax look like? I can read a tab-delimited file that contains values with 12 decimals without any problems.

 


From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Roberts, Michael
Sent: Thursday, May 21, 2009 10:37 AM
To: [hidden email]
Subject: ver. 17 problem reading in decimals

 

Good Morning Listers,

 

Have a condition not encountered before, and wonder if anyone else has – my data, a tab delimited text file has several numeric fields with about 12 decimals.  When reading in these data if I set the decimals value (Fx.x) to over 7 I get errors.  Setting the value to 7 or less works.  Is this a glitch or intentional, and if intentional, how can I get around it?

 

TIA

 

Mike

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Re: ver. 17 problem reading in decimals

Oliver, Richard

You have a 5 GB text file from which read only the first 9,000 cases, and you end up with a 10 GB SAV file?

 


From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Roberts, Michael
Sent: Thursday, May 21, 2009 2:37 PM
To: [hidden email]
Subject: Re: ver. 17 problem reading in decimals

 

Richard,

 

One more question – my original uncompressed text file was about 5gb.  After I saved it as a .SAV file it grew to 10gb.  Is this normal?

 

Thanking You

Sincerely

 

Mike

 

From: Oliver, Richard [mailto:[hidden email]]
Sent: Thursday, May 21, 2009 3:29 PM
To: Roberts, Michael; [hidden email]
Subject: RE: Re: ver. 17 problem reading in decimals

 

Right. There was a known issue with the Text Wizard, which I think has been resolved for the next release. You cannot specify a format value that contains more than 16 decimal positions, but the Text Wizard was attempting to do so. Keep in mind that double-precision floating point values are basically limited to 16 digits of precision. So if you really have 21-digit values with 19 decimals, these values cannot be represented precisely in SPSS (except as strings).

 

All the folks out there who actually know something about computers will correct me if I’m wrong.

 


From: Roberts, Michael [mailto:[hidden email]]
Sent: Thursday, May 21, 2009 2:04 PM
To: Oliver, Richard; [hidden email]
Subject: RE: Re: ver. 17 problem reading in decimals

 

Hi Richard,

 

I have run a few tests varying the number of decimals and the following is what seems to be the case:

 

Up to 16 decimals there are no problems; I varied the decimals from F20.19 through F20.15, and at F20.16 there were no errors.  Syntax is generated by the dialogue box (wanted to see what SPSS was seeing) – the bit with the relevant variables is included:

“...

GET DATA

  /TYPE=TXT

  /FILE='<<filepath>>’

  /DELCASE=LINE

  /DELIMITERS=","

  /ARRANGEMENT=DELIMITED

  /FIRSTCASE=2

  /IMPORTCASE=FIRST 9000

  /VARIABLES=

.

.

.

  on_risk A1

  demoscore F21.19

  demofact F1.0

  rxscore F20.17

  rxfact F1.0

  totscore F21.19

  adjscore F21.19

CACHE.

EXECUTE.

DATASET NAME DataSet3 WINDOW=FRONT.

 

The error I get when running the code as is –

Error.  Command name: GET DATA

(2265) Unrecognized or invalid variable definition.

This command not executed.

CACHE.

EXECUTE.

 

Error # 105.  Command name: EXECUTE

This command is not valid before a working file has been defined.

This command not executed.

DATASET NAME DataSet3 WINDOW=FRONT.”

 

When changing the decimal value to 16 (F21.16), the file reads in OK.  Is this a documented limitation of the decimals, or just a bug?

 

TIA

 

Mike

 

 

From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Oliver, Richard
Sent: Thursday, May 21, 2009 12:54 PM
To: [hidden email]
Subject: Re: ver. 17 problem reading in decimals

 

What kind of errors? What does the syntax look like? I can read a tab-delimited file that contains values with 12 decimals without any problems.

 


From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Roberts, Michael
Sent: Thursday, May 21, 2009 10:37 AM
To: [hidden email]
Subject: ver. 17 problem reading in decimals

 

Good Morning Listers,

 

Have a condition not encountered before, and wonder if anyone else has – my data, a tab delimited text file has several numeric fields with about 12 decimals.  When reading in these data if I set the decimals value (Fx.x) to over 7 I get errors.  Setting the value to 7 or less works.  Is this a glitch or intentional, and if intentional, how can I get around it?

 

TIA

 

Mike

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Re: ver. 17 problem reading in decimals

Oliver, Richard
In reply to this post by Roberts, Michael

If SAS stores numbers as double-precision floating point values, then you should have issues with values that exceed 16 digits of precision.

 


From: Roberts, Michael [mailto:[hidden email]]
Sent: Thursday, May 21, 2009 2:33 PM
To: Oliver, Richard; [hidden email]
Subject: RE: Re: ver. 17 problem reading in decimals

 

Richard,

 

Thank you for your help with this.  Do you know whether SAS would be subject to a similar limitation?  The problem was originally discovered with that app.

 

Sincerely

Mike 

 

From: Oliver, Richard [mailto:[hidden email]]
Sent: Thursday, May 21, 2009 3:29 PM
To: Roberts, Michael; [hidden email]
Subject: RE: Re: ver. 17 problem reading in decimals

 

Right. There was a known issue with the Text Wizard, which I think has been resolved for the next release. You cannot specify a format value that contains more than 16 decimal positions, but the Text Wizard was attempting to do so. Keep in mind that double-precision floating point values are basically limited to 16 digits of precision. So if you really have 21-digit values with 19 decimals, these values cannot be represented precisely in SPSS (except as strings).

 

All the folks out there who actually know something about computers will correct me if I’m wrong.

 


From: Roberts, Michael [mailto:[hidden email]]
Sent: Thursday, May 21, 2009 2:04 PM
To: Oliver, Richard; [hidden email]
Subject: RE: Re: ver. 17 problem reading in decimals

 

Hi Richard,

 

I have run a few tests varying the number of decimals and the following is what seems to be the case:

 

Up to 16 decimals there are no problems; I varied the decimals from F20.19 through F20.15, and at F20.16 there were no errors.  Syntax is generated by the dialogue box (wanted to see what SPSS was seeing) – the bit with the relevant variables is included:

“...

GET DATA

  /TYPE=TXT

  /FILE='<<filepath>>’

  /DELCASE=LINE

  /DELIMITERS=","

  /ARRANGEMENT=DELIMITED

  /FIRSTCASE=2

  /IMPORTCASE=FIRST 9000

  /VARIABLES=

.

.

.

  on_risk A1

  demoscore F21.19

  demofact F1.0

  rxscore F20.17

  rxfact F1.0

  totscore F21.19

  adjscore F21.19

CACHE.

EXECUTE.

DATASET NAME DataSet3 WINDOW=FRONT.

 

The error I get when running the code as is –

Error.  Command name: GET DATA

(2265) Unrecognized or invalid variable definition.

This command not executed.

CACHE.

EXECUTE.

 

Error # 105.  Command name: EXECUTE

This command is not valid before a working file has been defined.

This command not executed.

DATASET NAME DataSet3 WINDOW=FRONT.”

 

When changing the decimal value to 16 (F21.16), the file reads in OK.  Is this a documented limitation of the decimals, or just a bug?

 

TIA

 

Mike

 

 

From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Oliver, Richard
Sent: Thursday, May 21, 2009 12:54 PM
To: [hidden email]
Subject: Re: ver. 17 problem reading in decimals

 

What kind of errors? What does the syntax look like? I can read a tab-delimited file that contains values with 12 decimals without any problems.

 


From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Roberts, Michael
Sent: Thursday, May 21, 2009 10:37 AM
To: [hidden email]
Subject: ver. 17 problem reading in decimals

 

Good Morning Listers,

 

Have a condition not encountered before, and wonder if anyone else has – my data, a tab delimited text file has several numeric fields with about 12 decimals.  When reading in these data if I set the decimals value (Fx.x) to over 7 I get errors.  Setting the value to 7 or less works.  Is this a glitch or intentional, and if intentional, how can I get around it?

 

TIA

 

Mike

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Re: ver. 17 problem reading in decimals

Roberts, Michael

Thank you again, Richard.   This resolves our mystery!

 

Regards

Mike

 

From: Oliver, Richard [mailto:[hidden email]]
Sent: Thursday, May 21, 2009 3:48 PM
To: Roberts, Michael; [hidden email]
Subject: RE: Re: ver. 17 problem reading in decimals

 

If SAS stores numbers as double-precision floating point values, then you should have issues with values that exceed 16 digits of precision.

 


From: Roberts, Michael [mailto:[hidden email]]
Sent: Thursday, May 21, 2009 2:33 PM
To: Oliver, Richard; [hidden email]
Subject: RE: Re: ver. 17 problem reading in decimals

 

Richard,

 

Thank you for your help with this.  Do you know whether SAS would be subject to a similar limitation?  The problem was originally discovered with that app.

 

Sincerely

Mike 

 

From: Oliver, Richard [mailto:[hidden email]]
Sent: Thursday, May 21, 2009 3:29 PM
To: Roberts, Michael; [hidden email]
Subject: RE: Re: ver. 17 problem reading in decimals

 

Right. There was a known issue with the Text Wizard, which I think has been resolved for the next release. You cannot specify a format value that contains more than 16 decimal positions, but the Text Wizard was attempting to do so. Keep in mind that double-precision floating point values are basically limited to 16 digits of precision. So if you really have 21-digit values with 19 decimals, these values cannot be represented precisely in SPSS (except as strings).

 

All the folks out there who actually know something about computers will correct me if I’m wrong.

 


From: Roberts, Michael [mailto:[hidden email]]
Sent: Thursday, May 21, 2009 2:04 PM
To: Oliver, Richard; [hidden email]
Subject: RE: Re: ver. 17 problem reading in decimals

 

Hi Richard,

 

I have run a few tests varying the number of decimals and the following is what seems to be the case:

 

Up to 16 decimals there are no problems; I varied the decimals from F20.19 through F20.15, and at F20.16 there were no errors.  Syntax is generated by the dialogue box (wanted to see what SPSS was seeing) – the bit with the relevant variables is included:

“...

GET DATA

  /TYPE=TXT

  /FILE='<<filepath>>’

  /DELCASE=LINE

  /DELIMITERS=","

  /ARRANGEMENT=DELIMITED

  /FIRSTCASE=2

  /IMPORTCASE=FIRST 9000

  /VARIABLES=

.

.

.

  on_risk A1

  demoscore F21.19

  demofact F1.0

  rxscore F20.17

  rxfact F1.0

  totscore F21.19

  adjscore F21.19

CACHE.

EXECUTE.

DATASET NAME DataSet3 WINDOW=FRONT.

 

The error I get when running the code as is –

Error.  Command name: GET DATA

(2265) Unrecognized or invalid variable definition.

This command not executed.

CACHE.

EXECUTE.

 

Error # 105.  Command name: EXECUTE

This command is not valid before a working file has been defined.

This command not executed.

DATASET NAME DataSet3 WINDOW=FRONT.”

 

When changing the decimal value to 16 (F21.16), the file reads in OK.  Is this a documented limitation of the decimals, or just a bug?

 

TIA

 

Mike

 

 

From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Oliver, Richard
Sent: Thursday, May 21, 2009 12:54 PM
To: [hidden email]
Subject: Re: ver. 17 problem reading in decimals

 

What kind of errors? What does the syntax look like? I can read a tab-delimited file that contains values with 12 decimals without any problems.

 


From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Roberts, Michael
Sent: Thursday, May 21, 2009 10:37 AM
To: [hidden email]
Subject: ver. 17 problem reading in decimals

 

Good Morning Listers,

 

Have a condition not encountered before, and wonder if anyone else has – my data, a tab delimited text file has several numeric fields with about 12 decimals.  When reading in these data if I set the decimals value (Fx.x) to over 7 I get errors.  Setting the value to 7 or less works.  Is this a glitch or intentional, and if intentional, how can I get around it?

 

TIA

 

Mike

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Re: ver. 17 problem reading in decimals

Richard Ristow
In reply to this post by Roberts, Michael
At 03:29 PM 5/21/2009, Oliver, Richard wrote:

>Double-precision floating point values are basically limited to 16
>digits of precision. So if you really have 21-digit values with 19
>decimals, these values cannot be represented precisely in SPSS

At 03:33 PM 5/21/2009, Roberts, Michael wrote:

>Do you know whether SAS would be subject to a similar limitation?

This comes up from time to time. SPSS, SAS, and many other modern
systems use what are called "IEEE-754 64-bit numbers"(*); SAS's
limitations will be exactly the same as SPSS's.

It is commonly stated that the precision is 16 digits. It's actually
53 bits, which is close but not quite identical. The 53 bits can
represent all integers from 0 through 9,007,199,254,740,992; that is,
all 15-digit integers and most, BUT NOT ALL, 16-digit integers.

As Richard Oliver wrote, numbers with 17 or more decimal digits can
be represented only to a close approximation.

........................
(*)IEEE is the Institute of Electrical and Electronic Engineers.
'IEEE 754 numbers' are numbers in a format described in 'IEEE 754',
i.e the 754th standard in the IEEE's ongoing program of developing
relevant standards.

IEEE 754 is widely used, first, because it's a pretty good standard.
And second, most modern computers have hardware to do arithmetic with
IEEE 754 numbers, so calculations are fast and easy to program.

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Re: ver. 17 problem reading in decimals

Roberts, Michael
Hi Richard,

Thank you very much for the clear explanation.  Not sure why our data
has these decimals, but this is a good occasion to revisit the data!

Sincerely
Mike

-----Original Message-----
From: Richard Ristow [mailto:[hidden email]]
Sent: Friday, May 22, 2009 6:22 PM
To: Roberts, Michael; [hidden email]
Cc: Oliver, Richard
Subject: Re: ver. 17 problem reading in decimals

At 03:29 PM 5/21/2009, Oliver, Richard wrote:

>Double-precision floating point values are basically limited to 16
>digits of precision. So if you really have 21-digit values with 19
>decimals, these values cannot be represented precisely in SPSS

At 03:33 PM 5/21/2009, Roberts, Michael wrote:

>Do you know whether SAS would be subject to a similar limitation?

This comes up from time to time. SPSS, SAS, and many other modern
systems use what are called "IEEE-754 64-bit numbers"(*); SAS's
limitations will be exactly the same as SPSS's.

It is commonly stated that the precision is 16 digits. It's actually
53 bits, which is close but not quite identical. The 53 bits can
represent all integers from 0 through 9,007,199,254,740,992; that is,
all 15-digit integers and most, BUT NOT ALL, 16-digit integers.

As Richard Oliver wrote, numbers with 17 or more decimal digits can
be represented only to a close approximation.

........................
(*)IEEE is the Institute of Electrical and Electronic Engineers.
'IEEE 754 numbers' are numbers in a format described in 'IEEE 754',
i.e the 754th standard in the IEEE's ongoing program of developing
relevant standards.

IEEE 754 is widely used, first, because it's a pretty good standard.
And second, most modern computers have hardware to do arithmetic with
IEEE 754 numbers, so calculations are fast and easy to program.

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