Time Generator Node and Flow Variable Input

KNIME Analytics Platform
1

Dear all,

I cannot convince the Time Generator node to respect external variable input. I want to provide a start and end date through the flow variables. This only works with number-of-generated-rows variable.

I suspect this problem is due to posix time being long and not int. I tried to overcome this with double and string without success. Also setting output variables causes an out of range error.

This is sad, as I cannot use this node in an automated fashion which practically makes it useless in my case. Any suggestions?

With best regards,
Max

2

Hi,

I experienced these problems too, without support of datetime variables it is difficult to do many tasks in financial analysis. Hope next versions will fix it.

I solved problem with Time Generator using PostgreSQL and DatabaseReader. If you use PostgreSQL (maybee other database systems like MS SQL Server), you can make queries like:

SELECT time::timestamp(0) FROM
generate_series('$${Sfrom}$$', '$${Sto}$$', interval '1 minute') time(i)

which returns exactly what you wants. 'from' and 'to' are string (formatted date) variables. Hope it helps.

3

Hi,

there seem to be various workarounds - another flavour is to use an R snippet as attached.

With best regards,
Max

4

This problem still persists in the current version of Knime 2.11.2

As a feature request it would be nice to select an interval to which the time series is generated e.g. 15min as in R (in addition to input number of rows).

5

Agreeing that being able to pass Flow Variables to the Time Generator node would be extremely helpful. For my purposes, the node is unusable without such a feature.

6

{duplicate}

7

Hi,

in cases like this, you can generate your own node :)

We don't have date/time variables, hence you need to convert them to a string. Take a look into the attached workflow to see how this works.

The workflow generates all dates between the current time and a fixed start date.

Best, Iris

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