Fit function to data points

Questions
1

I am trying to fit one of the following exponential functions:
Single function:

f(x) = A Exp{0.246914 (Bx + Cx + Dx Tan[(Ex)/Abs[x]] + Fx Tan[(Gx)/Abs[x]])} 
or

Piecewise function:

f(x) = H Exp{0.246914 (Jx + Kx * Tan[(Lx)/Abs[x]]} when x <= 6.01,
f(x) = M Exp{0.246914 (Nx + Px * Tan[(Qx)/Abs[x]]} when x  > 6.01

where A-Q are my parameters to estimate, to the following data points in the form of {x, y ± SD}:

Data = {{-25.0557, 46.2353 ± 3.6647}, {-20.0402, 19.8755 ± 1.3245}, {-14.9826, 8.81128 ± 0.70872}, {-10.0622, 4.55529 ± 0.42471}, {-6.99956, 5.07824 ± 0.48176}, {-5.9132, 4.10301 ± 0.65699}, {-5.46469, 2.86411}, {-4.95324, 2.24395}, {-4.50649, 2.24285},
{-3.99629, 2.50684}, {-3.42064, 1.62128}, {-2.97376, 1.53177}, {-2.46419, 2.23783},
{-2.01618, 1.35258}, {-1.56993, 1.70514}, {-0.994403, 0.907996}, {0.0269966, 0.728654},
{1.99718, 6.55914 ± 0.89086}, {4.03483, 9.82546 ± 1.37454}, {6.00577, 15.1255 ± 1.6745},
{7.98462, 14.8553 ±1.3447}, {9.00413, 16.0022 ± 1.7978}, {9.96008, 16.9724 ± 1.4276},
{10.9822, 16.2626 ± 1.7374}, {11.9967, 20.9461 ± 2.2539}, {14.9932, 23.149 ± 2.351},
{16.9673, 26.2387 ± 2.9613}, {19.8972, 30.3869 ± 4.2131}}

so, how can I get the best fit to these data points? Thank you for your help on this matter.

2

Have you tried NonlinearModelFit? You’ll also need to format your equations using square brackets rather than curly brackets and separate x from the coefficients with a space.

3

Jim, Sorry for the typos in my question as it was just for the clear presentation of the question. I got the fit using the piecewise function. Thanks.