String interpolation

Another interesting difference between double- and single-quoted strings is what happens when a variable is embedded inside a string. In double-quoted strings, the variable is expanded to its contents, a process known as string interpolation. This can aid readability considerably ... 

The user can precisely control whether variable interpolation occurs in double-quoted strings by placing a backslash in front of variables that should not be interpolated. 

Variable interpolation only extends to the contents of the variable itself. Perl will not try to evaluate arithmetic expressions or other programming statements that are embedded in double-quoted strings. For example, the statements... 

For each line read in this way, the while loop executes three statements. The first statement calls chomp to remove the newline character from the end of line. The second statement uses variable interpolation to insert the input line into the string "You typed line n n" and then prints the resulting string out. The last statement displays the prompt again. The result looks like this ... 

Fig. 5 Voronoi tessellation of the MEEP as projected onto the first two principal components PCI and PC2 in OP space. The black dots represent the initial configurations (converged SMCV string plus interpolation of additional replicas) used in the Markovian milestoning simulations. Projections of representative configurations obtained from the milestoning procedure are also shown using different colors. The region corresponding to the peak of the PMF and free energy curves (Figs. 4 and 6) is labeled...

In long-distance interval one calculates the potential in a model which is assumed to be a good approximation to QCD, usually in lattice QCD, but also in string and flux-tube models. One can use a smooth interpolating function for the transition region, smoothly join the non-perturbative potential to the perturbative one or simply add the perturbative and nonperturbative contributions. 

Spectra that have been measured on FT-IR spectrometers consist of a string of intensity values at equally spaced intervals. The discrete nature of the data has two results. First, it is highly unlikely that the maximum absorption of any band will correspond exactly with one of these data points. In addition, the slope of the spectrum can appear to change markedly from one point to the next (see Figure 10.1a). To eliminate these problems, some form of interpolation or alternative data processing is necessary. One of the most useful of these is zero filling [10]. 

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