What causes "Random count must be positive." in StockSharp/StockSharp?

Pass a positive integer for randomCount (e.g. at least 1; typically tens or hundreds for meaningful coverage).

StockSharp/StockSharp · error · ArgumentOutOfRangeException

Random count must be positive.

Error message

Random count must be positive.

What it means

Thrown by ToBruteForceRandom when randomCount <= 0. randomCount is the number of random samples drawn per optimizable parameter; a non-positive count produces no samples, so it is rejected with ArgumentOutOfRangeException.

Source

Thrown at Algo.Strategies/StrategyParamHelper.cs:674

	/// <returns>Lazy enumerable of strategy clones with their parameter arrays.</returns>
	public static IEnumerable<(Strategy strategy, IStrategyParam[] parameters)> ToBruteForceRandom(
		this Strategy strategy,
		IStrategyParam[] parameters,
		int randomCount,
		out IStrategyParam[] optimizedParams,
		out int totalCount)
	{
		if (strategy is null)
			throw new ArgumentNullException(nameof(strategy));

		if (parameters is null)
			throw new ArgumentNullException(nameof(parameters));

		if (parameters.Length == 0)
			throw new ArgumentOutOfRangeException(nameof(parameters), "No optimization parameters.");

		if (randomCount <= 0)
			throw new ArgumentOutOfRangeException(nameof(randomCount), "Random count must be positive.");

		var singleParams = new List<IStrategyParam>();
		var optimizeDict = new Dictionary<string, (IStrategyParam param, HashSet<object> values)>();

		foreach (var param in parameters)
		{
			if (!param.CanOptimize || param.OptimizeFrom is null || param.OptimizeTo is null)
			{
				singleParams.Add(param);
				continue;
			}

			var values = new HashSet<object>();

			for (var i = 0; i < randomCount; i++)
			{
				var randomValue = param.GetRandom(strategy.RandomProvider);
				if (randomValue is not null)

View on GitHub (pinned to 601a191de6)

Solutions

Pass a positive integer for randomCount (e.g. at least 1; typically tens or hundreds for meaningful coverage).
Clamp/validate the source value before calling: randomCount = Math.Max(1, configuredCount).
Bind the UI input to a numeric up-down with a minimum of 1.

Example fix

// before
var runs = strategy.ToBruteForceRandom(opt, configuredSamples, out _, out _); // configuredSamples == 0 -> throws

// after
var samples = Math.Max(1, configuredSamples);
var runs = strategy.ToBruteForceRandom(opt, samples, out _, out _);

Defensive patterns

Strategy: validation

Validate before calling

var samples = Math.Max(1, configuredSampleCount);
strategy.ToBruteForceRandom(opt, samples, out _, out _);

Prevention

Bind sample-size inputs to a numeric control with minimum 1.
Clamp computed sample counts to at least 1 before passing.

When it happens

Trigger: Calling strategy.ToBruteForceRandom(parameters, randomCount, ...) with randomCount set to 0 or a negative value — e.g. a UI/config value that defaulted to 0 or was parsed from an empty input.

Common situations: User-facing 'sample size' field left blank or set to 0; randomCount derived from a calculation (e.g. budget / cost) that rounded down to 0; passing an uninitialized int field.

Related errors

AI-assisted analysis of StockSharp/StockSharp@601a191de6 (2026-08-13). Data as JSON: /api/errors/06f6365d34e6e326. Report an issue: GitHub.