Another project, another question.... Below are two tables. Table A is daily stock data showing date, daily low, and daily high (columns 0, 1, 2). Table B is stock pivots only (based on a particular percentage between them), showing date and whether the pivot was a top (T) or a bottom (B) (columns 0, 1). Table C is the output I want, showing date, pivot, low, and high (columns 0, 1, 2, 3).
Table A: 2020-05-04,119.39,121.97 2020-05-05,122.47,124.31 2020-05-06,122.41,124.05 2020-05-07,121.06,123.26 2020-05-08,121.06,123.23 2020-05-11,120.67,123.45 2020-05-12,120.26,124.31 2020-05-13,114.84,119.98 2020-05-14,111.81,117.09 2020-05-15,115.25,117.39 2020-05-18,119.75,122.36 2020-05-19,120.14,122.17 2020-05-20,120.59,122.47 2020-05-21,118.97,121.72 2020-05-22,117.59,119.47 2020-05-26,121.01,122.62 2020-05-27,123.47,125.83 Table B: 2020-05-04,B 2020-05-05,T 2020-05-14,B 2020-05-20,T 2020-05-22,B Table C: 2020-05-04,B,119.39,121.97 2020-05-05,T,122.47,124.31 2020-05-06,,122.41,124.05 2020-05-07,,121.06,123.26 2020-05-08,,121.06,123.23 2020-05-11,,120.67,123.45 2020-05-12,,120.26,124.31 2020-05-13,,114.84,119.98 2020-05-14,B,111.81,117.09 2020-05-15,,115.25,117.39 2020-05-18,,119.75,122.36 2020-05-19,,120.14,122.17 2020-05-20,T,120.59,122.47 2020-05-21,,118.97,121.72 2020-05-22,B,117.59,119.47 2020-05-26,,121.01,122.62 2020-05-27,,123.47,125.83 (1) Am I correct to first create another column in Table A between columns 0 and 1? (2) In J, is it preferable for that inserted column to be empty or to contain spaces for this particular purpose? Table C will be imported into Excel, and I don't think Excel cares one way or the other. I don't know if it will be a J problem amending (or whatever verb is best) if a literal character is attempted to be inserted into an empty box. (I've never had to do that before. I also know there's a first time for everything.) (3) The main idea is to match dates in Table B with dates in Table A, and, if there is a match, to insert the pivot value into column 1 (empty or spaces) in Table C. Is there a verb (or combination of verbs) that will accomplish that at once, or is this too complicated and it would be a better approach to use a "for" loop? (4) Eventually, specialized daily astronomical data will need to be inserted in another column, so I presume the adding technique for dates that the markets are closed that was shared with me a couple of weeks ago would be the approach to use here, too. Correct? Just FYI, after the full Table C is complete, it will be imported into Excel, where formulas will color each top pivot cell green and each bottom pivot cell red (in their respective columns). This will make analysis much easier than doing everything manually, as now. Many thanks in advance for help with this project! Harvey ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
