printf, print, msg

printf (string format, ...)

Prints text and variables in a log file and the message window in [Test] and [Trade] modes. This is a standard C function. It allows to display messages and variables.

print (int to, string format, ...)

Similar to printf, but prints text and variables to a target channel given by the to parameter, such as the log file, a .csv spreadsheet file, the HTML status page, or the performance report.

msg (string format, ...): int

Displays text and variables in a modal or nonmodal message box with [Yes] and [No] buttons, and waits for the user to click one of the buttons. Format strings beginning with '#' open a nonmodal box.

Returns

0 when [No] was clicked, 1 when [Yes] was clicked.

Parameters:

to	TO_WINDOW - print to the message window and the log file (default for printf). TO_LOG - print in [Test] mode only to the log file, in [Trade] and in STEPWISE mode also to the message window. TO_FILE - print in [Test] and [Trade] mode to the log file. TO_ANY - print in all modes to the message window and log file (= TO_WINDOW+TRAINMODE). TO_DIAG - print to the diag.txt file (see Verbose). Note that log files and diag.txt file are not yet open in the INITRUN. TO_ALERT - print to an alert box and stop black box recording when the ALERT flag is set for Verbose. TO_CSV - print to a file with the script name and extension ".csv" in the Data folder, for exporting data. TO_CSVHDR - print to the first line of the CSV file; for writing a header before writing the data.. TO_REPORT - print in the EXITRUN to the performance report, for displaying additional performance parameters. TO_HTML - print in [Trade] or in STEPWISE mode to the HTML file that displays the live trading status. HMTL format codes can be included in the text. TO_TITLE - print to the title bar. TO_INFO - print to the info field. print(TO_INFO, 0) displays the current account or simulation state in the info field. TO_PANEL - print to the caption bar of the current control panel. TO_CHART - print to the caption bar and - if PL_TITLE is set - to the title of the current chart. +TRAINMODE - print also in [Train] mode.
format	C-style format string, containing arbitrary text with placeholders for subsequent variables (see format codes). The placeholders begin with a percent sign '%' and define the format of the displayed number. Examples: "$%.2f" prints a var with a dollar symbol and 2 decimals; "%i" prints an int; "%+4.1f" prints a var with +/- sign, 4 digits, and one decimal. For printing float variables, use the %f placeholder and typecast them to (var).
...	Expressions or variables, one for each placeholder in the format text.

Remarks:

!! Since the above functions accept any number and type of parameters, variable types are not checked and not automatically converted. A wrong variable type in a printf call will produce wrong output - not only of the variable, but also of all subsequent variables - and can even cause a program crash. So make sure that variables match the format string precisely. If you print a predefined variable, use the correct placeholder for var, float, int, or string. For printing float variables, typecast them to (var) or (double), like this: printf("Profit: $%.2f",(var)TradeProfit). The printf function will not automatically promote a float to a double.
For printing a percent sign in the text, use "%%"; for a backslash, use "\\". A short list of C-style format strings can be found under format codes, a more detailed description in any C/C++ book.
For printing on a new line in the log or message window, begin the text with the linefeed symbol "\n". Otherwise printf appends the text to the end of the current line. For printing on a new line in a HTML file, begin the text with the tag "<br>".
For deleting the current line in the message window and replacing it with new content, begin the text with the carriage-return symbol "\r". This way running counters or similar effects can be realized.
The maximum text size depends on the print channel. For the message window it's about 2000 characters, for a file 20000 characters. Longer texts are clipped.
For printing into a string, use the sprintf or strf functions. For printing into a file, use the file_append function.
For printing with printf only to the log file and not to the window, add a "#" at the begin of the text (printf("#\n...",...);). In [Trade] mode log messages are also printed to the window.
For temporarily suppressing all printf messages, set Verbose |= SILENT.
For opening a nonmodal message box with the msg function, add a "#" at the begin of the text (msg("#...",...);). A nonmodal message box has an [Ok] and a [Cancel] button and does not wait for the user to click a button; the script just continues. When the user later clicks [Ok], the AFFIRMED flag is set (see example). An empty message (msg("#");) lets the nonmodal box disappear.
For refreshing the GUI so that printed messages are updated in the window, use the wait function.
For debugging purposes, the watch function is often more convenient than the printf function. It allows breakpoints, needs no format string, and prevents errors by printing wrong variable types.

Examples:

// printf example
var vPrice = 123.456;
float fDiscount = 1.5;
int nNumber = 77;
...
printf("\nPrice %.3f for %d items, total %.3f, discount %.1f%%",
  vPrice, nNumber, nNumber*vPrice, (var)fDiscount);

// HTML status message example
if(ATR(30) < Threshold)
  print(TO_HTML,"<br>Low volatility - ATR30 = %.3f",ATR(30));

// nonmodal box example
function run()
{
  if(is(INITRUN))
    msg("#Nonmodal message box.\nClick [Ok] to exit script!");
  if(is(AFFIRMED))
    quit("Ok!");
  Sleep(10);
}

// CSV file output example
function run()
{
  LookBack = 100;
  asset(Asset);
  print(TO_CSVHDR,"Date,Price,SMA,EMA\n");
  print(TO_CSV,"%s,%.4f,%.4f,%.4f\n",
    strdate(YMDHMS,0),
    priceC(),
    SMA(seriesC(),50),
    EMA(seriesC(),50));
}