# Table/list: find the last real number element of each row to constitute a list

I have a list (Table), mostly composed of real numbers. The list also contains some non-real elements. The list is similar to the following (but much much larger):

{{0.11011887269, 0.02087291466, 0.02082444233, 0.02083704779,
0.02084940959, 0.02086181292, 0.02087425501, 0.02088673503,
0.02089925331, 0.02091181001, 0.02092440529, 0.02093703933,
0.02094971232, 0.02096242441, test1[18, 15]}, {0.10941526373,
0.017604005802, 0.017549654594, 0.017558686829, test1[19, 5],
test1[19, 6], test1[19, 7], test1[19, 8], test1[19, 9],
test1[19, 10], test1[19, 11], test1[19, 12], test1[19, 13],
test1[19, 14], test1[19, 15]}, {0.10890647143, 0.014986243752,
0.014927392616, 0.014934004368, test1[20, 5], test1[20, 6],
test1[20, 7], test1[20, 8], test1[20, 9], test1[20, 10],
test1[20, 11], test1[20, 12], test1[20, 13], test1[20, 14],
test1[20, 15]}}


I would like to construct a single row or column list that preserves the last real number element of each row of the above list. For example, with the above table, the resulting list should contain only 3 elements as:

{0.02096242441, 0.017558686829, 0.014934004368}


How can this resulting list be automatically constructed from the original one?

• How about Table[Last[Cases[row, _Real]], {row, d}] where d is your list Apr 19, 2021 at 1:47
• @MelaGo This is exactly what I needed. Thanks. Apr 19, 2021 at 1:59

With table your list of lists:

Cases[table, {___, a_?NumericQ, Except[_?NumericQ] ...} :> a, All]

{0.0209624, 0.0175587, 0.014934}

SequenceCases[list, {{__, a_Real, __test1}} -> a]


{0.0209624, 0.0175587, 0.014934}

Using SplitBy:

Last@#1 & @@@ (SplitBy[#, Head] & /@ list)

(*{0.0209624, 0.0175587, 0.014934}*)


Or using ReplaceList:

ReplaceList[list, {___, s : {__, a_Real, __test1}, ___} :> a]

(*{0.0209624, 0.0175587, 0.014934}*)


Using Cases:

For each entry in list reversed, the Cases command can pick the first instance of _Real:

list = {{0.11011887269, 0.02087291466, 0.02082444233, 0.02083704779,
0.02084940959, 0.02086181292, 0.02087425501, 0.02088673503,
0.02089925331, 0.02091181001, 0.02092440529, 0.02093703933,
0.02094971232, 0.02096242441, test1[18, 15]}, {0.10941526373,
0.017604005802, 0.017549654594, 0.017558686829, test1[19, 5],
test1[19, 6], test1[19, 7], test1[19, 8], test1[19, 9],
test1[19, 10], test1[19, 11], test1[19, 12], test1[19, 13],
test1[19, 14], test1[19, 15]}, {0.10890647143, 0.014986243752,
0.014927392616, 0.014934004368, test1[20, 5], test1[20, 6],
test1[20, 7], test1[20, 8], test1[20, 9], test1[20, 10],
test1[20, 11], test1[20, 12], test1[20, 13], test1[20, 14],
test1[20, 15]}};

Cases[Reverse@#, _Real, 1, 1] & /@ list // Flatten[#, 1] &


Result:

{0.0209624, 0.0175587, 0.014934}