what is IW and LW ; how 3 layers ( output code of nprtool )

% Input 1

x1_step1.xoffset = 0;

x1_step1.gain = 0.200475452649894;

x1_step1.ymin = -1;

% Layer 1

b1 = [21;-18;-15;12;-9;6;-3;0;3;-6;-9;-12;15;-18;-21];

IW1_1 = [-21;21;21;-21;21;-21;21;-21;21;-21;-21;-21;21;-21;-21];

% Layer 2

b2 = [-1.5481522238423293114;-0.7740761119211646557;0;-0.7740761119211646557;1.5481522238423293114];

IW2_1 = [0.18591536098364511154;0.40639192253934214305;-0.27042472258088517956;-0.13412187216347298824;0.54252530242902852198];

LW2_1 = [0.24501255112064976305 -0.603300841276200428 -0.31452233587919281588 0.07939424409636260116 0.44177212706927815322 -0.40403354541199126837 0.50751435892984475551 -0.54319460220556725627 0.47092317372014752541 -0.014194546924077773228 0.11388969568404412602 -0.60856374907308730116 0.1199469037241999575 0.54482429435198376222 0.073698545566984838273;-0.32079984547876161383 -0.15570837924466876534 0.54270824861039013154 -0.012900971754842980449 -0.58084194695714630452 0.56199828111983707313 0.49164542229830543452 0.31541117114819716694 -0.59500114066111353672 0.28464496073269612841 -0.24308627374845612201 0.26317896635071003075 0.12964031314271853845 0.46422927590403095799 0.1400966963385319175;0.3661099146813505123 -0.088863383421529829054 0.50751759546088714981 -0.32434151025360968834 -0.23677560402537684014 0.060968908460366254276 -0.024648639739306959368 -0.51859575552674685994 0.48481885254804552021 -0.41902180208207762124 0.65900575796944338425 0.51813679145102342627 0.023153701831279262929 -0.54490372774253270638 -0.28066527042325184471;-0.28720257525894682393 -0.26883262902038468356 -0.14117619198974820649 0.67274961594904902906 0.34170048870571251287 -0.34148005050612378897 -0.07865734225189835449 -0.19791789712245583255 -0.29112457961187176991 -0.38974765887977130818 0.54393856786292726913 -0.5243254228375202608 -0.67653062572906819128 -0.19977619038530908258 0.4095533661557646532;-0.31425113275532029489 -0.29530014251238639877 -0.029059725654305205295 -0.44664224747398562076 0.20384193873498809846 0.11094219649895625812 -0.26579744335546978684 -0.14702767416474224471 -0.35250979683052890978 0.6725727859643003681 -0.43767651132380086532 -0.65088838030431739323 0.2667693286280342635 -0.36437893831932721689 0.4174388089989150008];

% Layer 3

b3 = -0.65223372011098734724;

IW3_1 = 0.56218453182077365859;

LW3_1 = [-0.29780313517079992636 -0.89140529220004594002 0.41740923395844964361 0.98585688260799231308 -0.67504702962022644641 -0.77286732265590618596 0.82575085177308693574 -0.036686039254889557526 0.70361190401670703487 0.61982760620841070853 -0.62648091146031958942 -0.50560028650867350208 -0.89162231726546115063 0.21792291290775667179 0.55446485846902082706];

LW3_2 = [0.022128178225443217997 -0.94449982310345648173 0.98077056313375110541 0.0018798475072103748573 -0.33600502607768722996];

% Output 1

y1_step1.ymin = -1;

y1_step1.gain = 0.2;

y1_step1.xoffset = 0;