Update README.md for executing examples

README.md

@@ -101,6 +101,98 @@ Which will put the library's header files and the application `<install_path>/in
 
 ## Usage
 
+TLDR;
+```
+ROOT Command Line Interface
+
+
+root_cli [OPTIONS] SUBCOMMAND
+
+
+OPTIONS:
+  -h,     --help              Print this help message and exit
+  -v,     --verbose           Enable verbose output
+          --wcli, --write-to-cli
+                              Write results to command line
+          --wcsv, --write-to-csv TEXT
+                              Path for writing results to CSV file
+          --ocsvsep, --output-csv-sep CHAR [,]
+                              Separator character for CSV output
+          --wdat, --write-to-dat TEXT
+                              Path for writing results to DAT file
+          --wgnuplot, --write-to-gnuplot TEXT
+                              Path for writing results to Gnuplot file
+          --ofmode, --output-file-mode CHAR:{a,o} [o]
+                              Append or overwrite output file: 'a' for append, 'o' for
+                              overwrite
+
+SUBCOMMANDS:
+  csv                         Use CSV input
+  dat                         Use DAT input
+  cli                         Use CLI input
+```
+
+Assuming that `root_cli` is on your `PATH`, the program can be executed with:
+
+```
+root_cli <arguments>
+# or use the full install/build path of the executable: /path/to/root_cli <arguments>
+```
+
+In order to print out more information about the arguments and the subcommands:
+
+```
+root_cli <arguments>
+```
+
+Every additional needed function must be added together with the function to find the root of.
+Here's a list of examples of possible execution syntax:
+
+- CLI input, CLI output, Newton-Raphson method to find the root of x^2-4, starting from initial guess 1 (default tolerance and maximum iterations):
+
+    ```
+    root_cli --wcli cli --function "x^2-4" newton --initial 1.0 --derivative "2*x"
+    ```
+
+- DAT input file called input.dat with first row not being header and " " separating different values, .dat file output called output.dat, Bisection method to find the root of x^3-1, with initial interval [-2,2], verbose output (given tolerance and maximum iterations):
+
+    ```
+    root_cli --verbose --wdat output dat input
+    ```
+
+    where input.dat is:
+
+    ```
+    function = x^3-1
+    method = bisection
+    initial = -1
+    tolerance = 1e-5
+    max-iterations = 100
+    derivative = 2*x
+    ```
+
+- CSV input file called input.csv with first row which is a header and "," separating different values, .csv file ouput
+called output.csv, Fixed Point Method to find the root of cos(x), with
+initial guess 0.5, fixed point function cos(x):
+
+    ```
+    root_cli --wcsv output --ocsvsep , csv input --sep , --header
+    ```
+
+    where input.csv is:
+
+    ```
+    function,method,initial,tolerance,max_iterations,g-function
+    'cos(x)',fixed_point,0.5,1e-5,100,'cos(x)'
+    ```
+
+- CLI input, .dat output file called output.dat and moreover a GNU Plot is created from it as output.png. Chords method to solve
+the equation x^3-8 starting from the two initial points 1 and 3:
+
+    ```
+    root_cli --wdat output --wgnuplot output cli --function x^3-8 chords --x0 --x1 3
+    ```
+
 The installed CLI application can simply be used by:
 
 ```

ROOT/ROOT/reader.cpp

@@ -107,10 +107,10 @@ std::unique_ptr<ConfigBase> ReaderBase::make_config_from_map(
     }
 
     int max_iter = 100;
-    auto it_max = config_map.find("max_iterations");
+    auto it_max = config_map.find("max-iterations");
     if (it_max != config_map.end()) {
         if (!parseInt(it_max->second, max_iter)) {
-            std::cerr << "\033[31mmake_config_from_map: invalid max_iterations: " << it_max->second << "\033[0m\n";
+            std::cerr << "\033[31mmake_config_from_map: invalid max-iterations: " << it_max->second << "\033[0m\n";
             std::exit(EXIT_FAILURE);
         }
     }
@@ -202,14 +202,14 @@ std::unique_ptr<ConfigBase> ReaderBase::make_config_from_map(
 
         case Method::FIXED_POINT: {
             auto it_x0 = config_map.find("initial");
-            auto it_g = config_map.find("function_g");
+            auto it_g = config_map.find("g-function");
             if (it_x0 == config_map.end() || it_g == config_map.end()) {
-                std::cerr << "\033[31mmake_config_from_map: fixed_point requires initial and function_g\033[0m\n";
+                std::cerr << "\033[31mmake_config_from_map: fixed_point requires initial and g-function\033[0m\n";
                 std::exit(EXIT_FAILURE);
             }
             double initial = 0.0;
-            auto function_g = FunctionParserBase::parseFunction(it_g->second);
-            return std::make_unique<FixedPointConfig>(tolerance, max_iter, aitken, function, initial, function_g,
+            auto g_function = FunctionParserBase::parseFunction(it_g->second);
+            return std::make_unique<FixedPointConfig>(tolerance, max_iter, aitken, function, initial, g_function,
                                                       verbose);
         }
     }  // switch
@@ -312,8 +312,8 @@ std::unique_ptr<ConfigBase> ReaderCSV::read(CLI::App* app, bool verbose) {
         }
     } else {
         // positional mapping documented here:
-        std::vector<std::string> posnames = {"method",     "tolerance",  "max_iterations", "aitken",     "function",
-                                             "derivative", "interval_a", "interval_b",     "function_g", "initial",
+        std::vector<std::string> posnames = {"method",     "tolerance",  "max-iterations", "aitken",     "function",
+                                             "derivative", "interval_a", "interval_b",     "function-g", "initial",
                                              "x0",         "x1"};
         for (size_t i = 0; i < values.size() && i < posnames.size(); ++i) {
             config_map[posnames[i]] = values[i];
@@ -383,7 +383,7 @@ std::unique_ptr<ConfigBase> ReaderCLI::read(CLI::App* app, bool verbose) {
     if (verbose) {
         std::cout << "ReaderCLI: read configuration\n";
         std::cout << "  tolerance = " << app->get_option("--tolerance")->as<double>() << "\n";
-        std::cout << "  max_iterations = " << app->get_option("--max-iterations")->as<int>() << "\n";
+        std::cout << "  max-iterations = " << app->get_option("--max-iterations")->as<int>() << "\n";
         std::cout << "  aitken = " << (app->get_option("--aitken")->as<bool>() ? "true" : "false") << "\n";
         std::cout << "  function = " << app->get_option("--function")->as<std::string>() << "\n";
         std::cout << "  verbose = " << (verbose ? "true" : "false") << "\n";
@@ -423,7 +423,7 @@ std::unique_ptr<ConfigBase> ReaderCLI::read(CLI::App* app, bool verbose) {
                 app->get_subcommand("fixed_point")->get_option("--g-function")->as<std::string>()),
             verbose);
         if (verbose) {
-            std::cout << "  g_function = "
+            std::cout << " g-function = "
                       << app->get_subcommand("fixed_point")->get_option("--g-function")->as<std::string>() << "\n";
             std::cout << "  initial = " << app->get_subcommand("fixed_point")->get_option("--initial")->as<double>()
                       << "\n";