Create a variable named lambdaEnd $(\backslash$lambda

end

$)$ that contains the value of the last wavelength in the recorded spectrum. You can calculate lambdaEnd with the expression $\backslash$lambda

start

$+($nObs$1)\backslash$lambda

delta

$.$

Use lambdaEnd to create a vector named lambda $(\backslash$lambda $)$ that contains the wavelengths in the spectrum, from $\backslash$lambda

start

to $\backslash$lambda

end

$,$ in steps of $\backslash$lambda

delta

$.$