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## [O] Calc: Multiply time (hours) with a float

 From: Karl Voit Subject: [O] Calc: Multiply time (hours) with a float Date: Thu, 8 Sep 2016 10:33:37 +0200 User-agent: slrn/pre1.0.0-18 (Linux)

```Hi!

I do have following situation: I'd like to multiply a float with hours
which results in an error, obviously. However, I was not able to find
out how to do it.

Minimal example with expected product:

| time [h:m:s] |   value |   product |
|--------------+---------+-----------|
|     09:15:00 | 2.54321 | 23.524693 |
#+TBLFM: @2\$3=\$2*\$1

In case you have time and energy to go deeper in my rabbit hole:

My real world example which is a bit more complex in case you want to
find a totally different way (workaround?) of calculating the stuff I
need:

First table determines the reference hours per day of my lawn mowing
robot with the current program:

#+NAME: robot-program
| Status As Of     | Start |   End | Start |   End | Hours/Day |
|------------------+-------+-------+-------+-------+-----------|
| <2016-06-30 Thu> | 11:30 | 19:30 | 20:30 | 21:45 |  09:15:00 |
#+TBLFM: \$6=(\$3-\$2)+(\$5-\$4);T

Second table holds the logged number of hours of work for certain time
stamps (first three columns). The thing I want to calculate is the
number of hours the robot was *supposed* to work. Unfortunately, the
robot gets stuck from time to time and therefore the logged working
hours differ from the theoretical working hours (reference).

For a better understanding, I split the calculation of \$6 (my desired
comparison value) and added \$4 (the daily hour reference value) and \$5
(difference between the current row and the previous one in time).

Current situation with the ERROR:

| Date                   | Hours | Difference [h] | Daily Reference |
Difference [Days] | Reference Comparison [h] |
|------------------------+-------+----------------+-----------------+-------------------+--------------------------|
| <2016-08-13 Sat>       |   100 |            100 |                 |
|                          |
| <2016-08-20 Sat 14:40> |   217 |            117 |        09:15:00 |
7.611111 | #ERROR                   |
| <2016-08-27 Sat 19:08> |   245 |             28 |        09:15:00 |
7.186111 | #ERROR                   |
#+TBLFM: \$3=\$2-subscr(@<\$2..@>\$2, @# - 1);N ::
@3\$4..@>\$4=remote(robot-program,@>\$6);T :: @3\$5..@>\$5=(\$1 - subscr(@<\$1..@>\$1,
@# - 1)) :: @3\$6..@>\$6= \$5 * \$4

Desired output:

| Date                   | Hours | Difference [h] | Daily Reference |
Difference [Days] | Reference Comparison [h] |
|------------------------+-------+----------------+-----------------+-------------------+--------------------------|
| <2016-08-13 Sat>       |   100 |            100 |                 |
|                          |
| <2016-08-20 Sat 14:40> |   217 |            117 |        09:15:00 |
7.611111 |                70.402777 |
| <2016-08-27 Sat 19:08> |   245 |             28 |        09:15:00 |
7.186111 |                66.471527 |

Nitpicking: yes, comparing reference*hours (of whole days) to log
values which were logged in-between working hours is not exact even
with zero percent stuck time. I'd like to have just a rough
comparison.

So if my desired output can be derived without multiplying hours to
floats: I'm open ;-)

--