How do you set to Double Precision mode for 34S?

[zeno333]

How do you set the 34S to Double Precision mode...I know its probably in the documentation, but cant seem to find it.

[Paul Dale]

In the MODE catalogue. Press D and you'll get to DBLOFF, you want DBLON which is immediately below.

Pauli

[zeno333]

(01-16-2017 03:35 AM)Paul Dale Wrote:  In the MODE catalogue. Press D and you'll get to DBLOFF, you want DBLON which is immediately below.

Pauli

OK, when you get there, how do you invoke that feature...?

[Dieter]

(01-16-2017 04:15 AM)zeno333 Wrote:  OK, when you get there, how do you invoke that feature...?

As usual: press ENTER or XEQ.

Dieter

[Paul Dale]

Perhaps you need the manual

- Pauli

[Leonid]

BTW there is no way to programmatically displays the 18 trailing digits in DP mode?

[Paul Dale]

I'm sure a program could be written to display the extra digits:

To get the second 12 digits:

set round to zero mode,
round to 12 digits,
subtract from the original number.

Do this again to get the final 10 digits.


Pauli

[Dieter]

(01-16-2017 09:37 PM)Paul Dale Wrote:  To get the second 12 digits:

set round to zero mode,

"Round to zero" is round mode 4, i.e. truncation (instead of the standard mode 0 that rounds to even).
The round mode is set by the RM command which is part of the MODE menu.

(01-16-2017 09:37 PM)Paul Dale Wrote:  round to 12 digits,

Round to 12 significant digits. This is accomplished by the RSD command that can be found in the X.FCN menu.

(01-16-2017 09:37 PM)Paul Dale Wrote:  subtract from the original number.

Yes. ;-)

So all in all it's a procedure like this:

Code:

RM 4                                  // set round mode to truncation
[SCI] 11                              // always show 12 significant digits

17 [1/X]         5,88235294118 E-2    // 1/17 rounded 12-digit display precision
[ENTER] RSD 12   5,88235294117 E-2    // first 12 digits
[-]              6,47058823529 E-14
[ENTER] RSD 12   6,47058823529 E-14   // next 12 digits
[-]              4,11764705800 E-26   // last 10 digits

RM 0                                  // reset standard round mode

Dieter