Symbols
wh = {x; = ih, h > 0, i = 1,2, ... ,N - 1, hN = l} - an equidistant
(uniforn1) grid on the interval (0, /);
wh = {x; = ih, h > 0, i = 0, 1, ... , N, hN = l} -an equidistant (nnifonn)
grid on the segment [O, /];
h - step of the grid wh;
.c = X; - a node of the grid wh;
y = Yi = y( X;) - a function defined on the grid w h;
Y.r = ( Y;+ 1 - Yi)/ h - the right difference derivative at a point xi;
:V.r = (Y; - y 1 _ 1 )/ h - the left difference derivative at a point x;;
~h.r = (Yi+i - 2y; + Y;- 1 )/h~ - the second difference derivativcc at a point
xi;
U!h = { X; E (0, l), i = 1, 2, ... , llf - 1} - a non-equidistant (nonuniform)
grid on the interval (O, l);wh = {x; E [O, /], i = 0,1, ... ,N, x 0 = 0, xN = l} - a non-equidistant
(nonuniform) grid on the segment [O, /];
h; = X; - X;_ 1 - step of the grid wh;
n; = o.5 (h; + h1+1);
Yx = (Yi+1 - y;) / h;+1,
Yx = (Y; - Y;-1)/h;;
Y:r = (Y;+1 - y;)/li;;
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