# How to combine list of data with different data length

Hi I have a question in the combining the data. I have a list of data from a DC stepper motor encoder which ish 49147 data points and a separate dataset from power analyzer recording the data at 100Hz for 1 min & 30sec, during the movement of the stepper motor.

Each system has a separate number of data points: DC stepper motor encoder read 49147 steps, and power analyzer has a total of 9005 data point.

How can I combine these two data point such that it can give a voltage to steps graph? Meaning x-axis is the stepper motor count and y axis is the voltage values.

Due to the huge data size, I have amend,the data by just taking the first 200, and 1000 data set from each measurement. Appreciate some help in this, thank you.

RS1Voltage10RPMA = Table[S1Voltage10RPMA[[i]], {i, 1, 200}]
{{1, 0.462338}, {2, 0.462268}, {3, 0.462292}, {4, 0.462267}, {5,0.462273}, {6, 0.462277}, {7, 0.462319}, {8, 0.462303}, {9,0.462339}, {10, 0.462355}, {11, 0.462341}, {12, 0.462366}, {13,0.46236}, {14, 0.462322}, {15, 0.462277}, {16, 0.462237}, {17,0.462258}, {18, 0.46231}, {19, 0.462275}, {20, 0.462283}, {21,0.462256}, {22, 0.46226}, {23, 0.462247}, {24, 0.462281}, {25, 0.46238}, {26, 0.462393}, {27, 0.462391}, {28, 0.462392}, {29, 0.462315}, {30, 0.462289}, {31, 0.462289}, {32, 0.462349}, {33, 0.462292}, {34, 0.462344}, {35, 0.462337}, {36, 0.462352}, {37, 0.462299}, {38, 0.462296}, {39, 0.462301}, {40, 0.462335}, {41, 0.462325}, {42, 0.462343}, {43, 0.462331}, {44, 0.46233}, {45, 0.462288}, {46, 0.462313}, {47, 0.462305}, {48, 0.462312}, {49, 0.462253}, {50, 0.462318}, {51, 0.462318}, {52, 0.462301}, {53, 0.462255}, {54, 0.462306}, {55, 0.462289}, {56, 0.462305}, {57, 0.462338}, {58, 0.462358}, {59, 0.462323}, {60, 0.462359}, {61, 0.462293}, {62, 0.462328}, {63, 0.462211}, {64, 0.462318}, {65, 0.462351}, {66, 0.462273}, {67, 0.462329}, {68, 0.462289}, {69, 0.462265}, {70, 0.462318}, {71, 0.462331}, {72, 0.462339}, {73, 0.462345}, {74, 0.462343}, {75, 0.462309}, {76, 0.46233}, {77,
0.462289}, {78, 0.462284}, {79, 0.462247}, {80, 0.462285}, {81,
0.462336}, {82, 0.462323}, {83, 0.462368}, {84, 0.462298}, {85, 0.46228}, {86, 0.462308}, {87, 0.462333}, {88, 0.462319}, {89,
0.462345}, {90, 0.462385}, {91, 0.462365}, {92, 0.462303}, {93,
0.462239}, {94, 0.46232}, {95, 0.462329}, {96, 0.462367}, {97,
0.462285}, {98, 0.462288}, {99, 0.462333}, {100, 0.462268}, {101,
0.462249}, {102, 0.462263}, {103, 0.46229}, {104, 0.462311}, {105,
0.462314}, {106, 0.462254}, {107, 0.462299}, {108, 0.462248}, {109,
0.462255}, {110, 0.462272}, {111, 0.462335}, {112, 0.462271}, {113, 0.462266}, {114, 0.462319}, {115, 0.462337}, {116, 0.462246}, {117,
0.462266}, {118, 0.462257}, {119, 0.462262}, {120, 0.462297}, {121,
0.462277}, {122, 0.462312}, {123, 0.462259}, {124, 0.462228}, {125,
0.462283}, {126, 0.462238}, {127, 0.46227}, {128, 0.462314}, {129, 0.462247}, {130, 0.462272}, {131, 0.462248}, {132, 0.462207}, {133,
0.462243}, {134, 0.462257}, {135, 0.462229}, {136, 0.46222}, {137,
0.462284}, {138, 0.462266}, {139, 0.462266}, {140, 0.462247}, {141,
0.462262}, {142, 0.462251}, {143, 0.462244}, {144, 0.462269}, {145,
0.462249}, {146, 0.462213}, {147, 0.462222}, {148, 0.462203}, {149,
0.462245}, {150, 0.462225}, {151, 0.462254}, {152, 0.462207}, {153,
0.462225}, {154, 0.462246}, {155, 0.462204}, {156, 0.462169}, {157,
0.4622}, {158, 0.462263}, {159, 0.462246}, {160, 0.46221}, {161,
0.462178}, {162, 0.462212}, {163, 0.46219}, {164, 0.462214}, {165,
0.462227}, {166, 0.462221}, {167, 0.462176}, {168, 0.462185}, {169,
0.462183}, {170, 0.462176}, {171, 0.46217}, {172, 0.46213}, {173,
0.462194}, {174, 0.462203}, {175, 0.462195}, {176, 0.462144}, {177,
0.462127}, {178, 0.46211}, {179, 0.462125}, {180, 0.462164}, {181,
0.462108}, {182, 0.462156}, {183, 0.462139}, {184, 0.462103}, {185,
0.462127}, {186, 0.462168}, {187, 0.462154}, {188, 0.462138}, {189,
0.462115}, {190, 0.462174}, {191, 0.462113}, {192, 0.462117}, {193,
0.462062}, {194, 0.462092}, {195, 0.462079}, {196, 0.462101}, {197,
0.462084}, {198, 0.462112}, {199, 0.462094}, {200, 0.46208}}

RS1encoderC10A = Table[S1ENC10A[[i]], {i, 1, 1000}]
{-1, -2, -3, -4, -5, -6, -7, -8, -9, -10, -11, -12, -13, -14, -15,
-16, -17, -18, -19, -20, -21, -22, -23, -24, -25, -26, -27, -28, -29, -30, -31, -32, -33, -34, -35, -36, -37, -38, -39, -40, -41, -42, -43, -44, -45, -46, -47, -48, -49, -50, -51, -52, -53, -54, -55, -56, -57, -58, -59, -60, -61, -62, -63, -64, -65, -66, -67, -68, -69, -70, -71,  -72, -73, -74, -75, -76, -77, -78, -79, -80, -81, -82, -83, -84, -85,  -86, -87, -88, -89, -90, -91, -92, -93, -94, -95, -96, -97, -98, -99, -100, -101, -102, -103, -104, -105, -106, -107, -108, -109, -110, -111, -112, -113, -114, -115, -116, -117, -118, -119, -120, -121, -122, -123, -124, -125, -126, -127, -128, -129, -130, -131, -132, -133, -134, -135, -136, -137, -138, -139, -140, -141, -142, -143, -144, -145, -146, -147, -148, -149, -150, -151, -152, -153, -154, -155, -156, -157, -158, -159, -160, -161, -162, -163, -164, -165,-166, -167, -168, -169, -170, -171, -172, -173, -174, -175, -176, -177, -178, -179, -180, -181, -182, -183, -184, -185, -186, -187, -188, -189, -190, -191, -192, -193, -194, -195, -196, -197, -198, -199, -200, -201, -202, -203, -204, -205, -206, -207, -208, -209,-210, -211, -212, -213, -214, -215, -216, -217, -218, -219, -220, -221, -222, -223, -224, -225, -226, -227, -228, -229, -230, -231, -232, -233, -234, -235, -236, -237, -238, -239, -240, -241, -242, -243, -244, -245, -246, -247, -248, -249, -250, -251, -252, -253,  -254, -255, -256, -257, -258, -259, -260, -261, -262, -263, -264, -265, -266, -267, -268, -269, -270, -271, -272, -273, -274, -275,-276, -277, -278, -279, -280, -281, -282, -283, -284, -285, -286, -287, -288, -289, -290, -291, -292, -293, -294, -295, -296, -297,-298, -299, -300, -301, -302, -303, -304, -305, -306, -307, -308, -309, -310, -311, -312, -313, -314, -315, -316, -317, -318, -319,  -320, -321, -322, -323, -324, -325, -326, -327, -328, -329, -330, -331, -332, -333, -334, -335, -336, -337, -338, -339, -340, -341, -342, -343, -344, -345, -346, -347, -348, -349, -350, -351, -352, -353, -354, -355, -356, -357, -358, -359, -360, -361, -362, -363, -364, -365, -366, -367, -368, -369, -370, -371, -372, -373, -374, -375, -376, -377, -378, -379, -380, -381, -382, -383, -384, -385, -386, -387, -388, -389, -390, -391, -392, -393, -394, -395, -396, -397, -398, -399, -400, -401, -402, -403, -404, -405, -406, -407,  -408, -409, -410, -411, -412, -413, -414, -415, -416, -417, -418,     -419, -420, -421, -422, -423, -424, -425, -426, -427, -428, -429,    -430, -431, -432, -433, -434, -435, -436, -437, -438, -439, -440,    -441, -442, -443, -444, -445, -446, -447, -448, -449, -450, -451,     -452, -453, -454, -455, -456, -457, -458, -459, -460, -461, -462,    -463, -464, -465, -466, -467, -468, -469, -470, -471, -472, -473,    -474, -475, -476, -477, -478, -479, -480, -481, -482, -483, -484,    -485, -486, -487, -488, -489, -490, -491, -492, -493, -494, -495,    -496, -497, -498, -499, -500, -501, -502, -503, -504, -505, -506,     -507, -508, -509, -510, -511, -512, -513, -514, -515, -516, -517,     -518, -519, -520, -521, -522, -523, -524, -525, -526, -527, -528,    -529, -530, -531, -532, -533, -534, -535, -536, -537, -538, -539,    -540, -541, -542, -543, -544, -545, -546, -547, -548, -549, -550,    -551, -552, -553, -554, -555, -556, -557, -558, -559, -560, -561,    -562, -563, -564, -565, -566, -567, -568, -569, -570, -571, -572,    -573, -574, -575, -576, -577, -578, -579, -580, -581, -582, -583,    -584, -585, -586, -587, -588, -589, -590, -591, -592, -593, -594,     -595, -596, -597, -598, -599, -600, -601, -602, -603, -604, -605,     -606, -607, -608, -609, -610, -611, -612, -613, -614, -615, -616,     -617, -618, -619, -620, -621, -622, -623, -624, -625, -626, -627,     -628, -629, -630, -631, -632, -633, -634, -635, -636, -637, -638,    -639, -640, -641, -642, -643, -644, -645, -646, -647, -648, -649,    -650, -651, -652, -653, -654, -655, -656, -657, -658, -659, -660,    -661, -662, -663, -664, -665, -666, -667, -668, -669, -670, -671,     -672, -673, -674, -675, -676, -677, -678, -679, -680, -681, -682,    -683, -684, -685, -686, -687, -688, -689, -690, -691, -692, -693,    -694, -695, -696, -697, -698, -699, -700, -701, -702, -703, -704,    -705, -706, -707, -708, -709, -710, -711, -712, -713, -714, -715,     -716, -717, -718, -719, -720, -721, -722, -723, -724, -725, -726,    -727, -728, -729, -730, -731, -732, -733, -734, -735, -736, -737,     -738, -739, -740, -741, -742, -743, -744, -745, -746, -747, -748,     -749, -750, -751, -752, -753, -754, -755, -756, -757, -758, -759,     -760, -761, -762, -763, -764, -765, -766, -767, -768, -769, -770,     -771, -772, -773, -774, -775, -776, -777, -778, -779, -780, -781,     -782, -783, -784, -785, -786, -787, -788, -789, -790, -791, -792,    -793, -794, -795, -796, -797, -798, -799, -800, -801, -802, -803,    -804, -805, -806, -807, -808, -809, -810, -811, -812, -813, -814,     -815, -816, -817, -818, -819, -820, -821, -822, -823, -824, -825,     -826, -827, -828, -829, -830, -831, -832, -833, -834, -835, -836,     -837, -838, -839, -840, -841, -842, -843, -844, -845, -846, -847,     -848, -849, -850, -851, -852, -853, -854, -855, -856, -857, -858,     -859, -860, -861, -862, -863, -864, -865, -866, -867, -868, -869,     -870, -871, -872, -873, -874, -875, -876, -877, -878, -879, -880,     -881, -882, -883, -884, -885, -886, -887, -888, -889, -890, -891,     -892, -893, -894, -895, -896, -897, -898, -899, -900, -901, -902,     -903, -904, -905, -906, -907, -908, -909, -910, -911, -912, -913,  -914, -915, -916, -917, -918, -919, -920, -921, -922, -923, -924,  -925, -926, -927, -928, -929, -930, -931, -932, -933, -934, -935,  -936, -937, -938, -939, -940, -941, -942, -943, -944, -945, -946,  -947, -948, -949, -950, -951, -952, -953, -954, -955, -956, -957,  -958, -959, -960, -961, -962, -963, -964, -965, -966, -967, -968,  -969, -970, -971, -972, -973, -974, -975, -976, -977, -978, -979,  -980, -981, -982, -983, -984, -985, -986, -987, -988, -989, -990,  -991, -992, -993, -994, -995, -996, -997, -998, -999, -1000}

• Please explain exactly how these datasets are related. I simply don't get it after reading the post three times. Please notice that this is a site about Mathematica, not about electrical engineering. You may try to use Interpolation to turn your datasets into functions and to plot them afterwards. Commented Oct 29, 2018 at 10:28
• Thank you Henrik, I was trying to plot the voltage on Y-axis and the stepper motor counts on X-axis. But I'm having a problem as they have different data points.
– ljsg
Commented Oct 29, 2018 at 11:00

If I read your question right, you want 9k voltage values mapped to 49k encoder points. The example below maps 9 voltage values to 49 points.

RS1encoderC10A = -Range[49];

RS1Voltage10RPMA = {{1, 0.462338}, {2, 0.462268}, {3, 0.462292},
{4, 0.462267}, {5, 0.462273}, {6, 0.462277}, {7, 0.462319},
{8, 0.462303}, {9, 0.462339}};

{e, v} = Length /@ {RS1encoderC10A, RS1Voltage10RPMA}
scale = MapThread[List, {N@Range[v/e, v, v/e], RS1encoderC10A}];
f = Interpolation[scale];
combined = Quiet[{f[#1], #2} & @@@ RS1Voltage10RPMA];

ListLinePlot[combined, AxesLabel -> {"encoder", "voltage"},
PlotMarkers -> Graphics[{PointSize[0.033], Point[{0, 0}]}],
ScalingFunctions -> {"Reverse", None}]


• Thank you Chris, I will give it a try.
– ljsg
Commented Oct 29, 2018 at 13:31