Re: [BLACKBOX] Big sums

From: Stephen R. Troy <"Stephen>
Date: Fri, 17 Jun 2011 07:57:41 -0700

----boundary-LibPST-iamunique-1099044961_-_- Content-type: text/plain Folks, I've been doing long numerical calculations for some 40 years, on every kind of machine you can imagine, some of them using operating systems. Long ago, sadder but wiser, I learned to do "checkpoints", i.e. (1) every so often, i.e. after a suitable time or number of iterations, write values of key variables to a file; when the program finishes it erases this file; (2) write the program so, on startup, it looks for the key variable file, and if present, starts using those values; if not, it asks the user for starting values. (3) program the computer (e.g., on a Windows machine, include in the Autoexec.bat file) to start the program on boot-up, so it will resume automatically after a power outage or other restart. That way the only thing lost is whatever was done after the last checkpoint. This always works and is independent of machine, language, or operating system. Steve Troy ---- To unsubscribe, send a message with body "SIGNOFF BLACKBOX" to LISTSERV{([at]})nowhere.xy ----boundary-LibPST-iamunique-1099044961_-_- Content-type: application/rtf Content-transfer-encoding: base64 Content-Disposition: attachment; filename="rtf-body.rtf" e1xydGYxXGFuc2lcYW5zaWNwZzEyNTJcZnJvbWh0bWwxIFxkZWZmMHtcZm9udHRibA0Ke1xmMFxm c3dpc3NcZmNoYXJzZXQwIEFyaWFsO30NCntcZjFcZm1vZGVybiBDb3VyaWVyIE5ldzt9DQp7XGYy XGZuaWxcZmNoYXJzZXQyIFN5bWJvbDt9DQp7XGYzXGZtb2Rlcm5cZmNoYXJzZXQwIENvdXJpZXIg TmV3O319DQp7XGNvbG9ydGJsXHJlZDBcZ3JlZW4wXGJsdWUwO1xyZWQwXGdyZWVuMFxibHVlMjU1 O30NClx1YzFccGFyZFxwbGFpblxkZWZ0YWIzNjAgXGYwXGZzMjQgDQp7XCpcaHRtbHRhZzE5IDxo dG1sPn0NCntcKlxodG1sdGFnNTAgPGJvZHk+fXtcKlxodG1sdGFnNjR9XGh0bWxydGYge1xodG1s cnRmMCANCntcKlxodG1sdGFnODQgPHNwYW4gc3R5bGU9ImZvbnQtZmFtaWx5OlZlcmRhbmE7IGNv bG9yOiMwMDAwMDA7IGZvbnQtc2l6ZToxMHB0OyI+fVxodG1scnRmIHtcaHRtbHJ0ZjAgXGh0bWxy dGYgfVxodG1scnRmMCB7XCpcaHRtbHRhZzcyfVxodG1scnRmfVxodG1scnRmMA0KDQp7XCpcaHRt bHRhZzk2IDxkaXY+fVxodG1scnRmIHtcaHRtbHJ0ZjAge1wqXGh0bWx0YWc2NH1caHRtbHJ0ZiB7 XGh0bWxydGYwIFxodG1scnRmIHtcaHRtbHJ0ZjAgRm9sa3MsIEkndmUgYmVlbiBkb2luZyBsb25n IG51bWVyaWNhbCBjYWxjdWxhdGlvbnMgZm9yIHNvbWUgNDAgeWVhcnMsIG9uIGV2ZXJ5IGtpbmQg b2YgbWFjaGluZSB5b3UgY2FuIGltYWdpbmUsIHNvbWUgb2YgdGhlbSB1c2luZyBvcGVyYXRpbmcg c3lzdGVtcy4NCntcKlxodG1sdGFnODQgJm5ic3A7fVxodG1scnRmIFwnYTBcaHRtbHJ0ZjAgIExv bmcgYWdvLCBzYWRkZXIgYnV0IHdpc2VyLCBJIGxlYXJuZWQgdG8gZG8gImNoZWNrcG9pbnRzIiwg aS5lLiBcaHRtbHJ0ZiB9XGh0bWxydGYwIHtcKlxodG1sdGFnNzJ9XGh0bWxydGZccGFyfVxodG1s cnRmMA0KDQp7XCpcaHRtbHRhZzEwNCA8L2Rpdj59XGh0bWxydGYgfVxodG1scnRmMCANCntcKlxo dG1sdGFnOTYgPGRpdj59XGh0bWxydGYge1xodG1scnRmMCB7XCpcaHRtbHRhZzY0fVxodG1scnRm IHtcaHRtbHJ0ZjAgXGh0bWxydGYge1xodG1scnRmMCAoMSkgZXZlcnkgc28gb2Z0ZW4sIGkuZS4g YWZ0ZXIgYSBzdWl0YWJsZSB0aW1lIG9yIG51bWJlciBvZiBpdGVyYXRpb25zLCB3cml0ZSB2YWx1 ZXMgb2Yga2V5IHZhcmlhYmxlcyB0byBhIGZpbGU7IHdoZW4gdGhlIHByb2dyYW0gZmluaXNoZXMg aXQgZXJhc2VzIHRoaXMgZmlsZTsNCntcKlxodG1sdGFnMTE2IDxicj59XGh0bWxydGYgXGxpbmUN ClxodG1scnRmMCBcaHRtbHJ0ZiB9XGh0bWxydGYwIHtcKlxodG1sdGFnNzJ9XGh0bWxydGZccGFy fVxodG1scnRmMA0KDQp7XCpcaHRtbHRhZzEwNCA8L2Rpdj59XGh0bWxydGYgfVxodG1scnRmMCAN CntcKlxodG1sdGFnOTYgPGRpdj59XGh0bWxydGYge1xodG1scnRmMCB7XCpcaHRtbHRhZzY0fVxo dG1scnRmIHtcaHRtbHJ0ZjAgXGh0bWxydGYge1xodG1scnRmMCAoMikgd3JpdGUgdGhlIHByb2dy YW0gc28sIG9uIHN0YXJ0dXAsIGl0IGxvb2tzIGZvciB0aGUga2V5IHZhcmlhYmxlIGZpbGUsIGFu ZCBpZiBwcmVzZW50LCBzdGFydHMgdXNpbmcgdGhvc2UgdmFsdWVzOyBpZiBub3QsIGl0IGFza3Mg dGhlIHVzZXIgZm9yIHN0YXJ0aW5nIHZhbHVlcy5caHRtbHJ0ZiB9XGh0bWxydGYwIHtcKlxodG1s dGFnNzJ9XGh0bWxydGZccGFyfVxodG1scnRmMA0KDQp7XCpcaHRtbHRhZzEwNCA8L2Rpdj59XGh0 bWxydGYgfVxodG1scnRmMCANCntcKlxodG1sdGFnOTYgPGRpdj59XGh0bWxydGYge1xodG1scnRm MCB7XCpcaHRtbHRhZzY0fVxodG1scnRmIHtcaHRtbHJ0ZjAgXGh0bWxydGYge1xodG1scnRmMCAo MykgcHJvZ3JhbSB0aGUgY29tcHV0ZXIgKGUuZy4sIG9uIGEgV2luZG93cyBtYWNoaW5lLCBpbmNs dWRlIGluIHRoZSANCntcKlxodG1sdGFnODQgPGEgaHJlZj0iaHR0cDovL0F1dG9leGVjLmJhdCI+ fVxodG1scnRmIHtcZmllbGR7XCpcZmxkaW5zdHtIWVBFUkxJTksgImh0dHA6Ly9BdXRvZXhlYy5i YXQifX17XGZsZHJzbHRcY2YxXHVsIFxodG1scnRmMCBBdXRvZXhlYy5iYXRcaHRtbHJ0ZiB9XGh0 bWxydGYwIFxodG1scnRmIH1caHRtbHJ0ZjAgDQp7XCpcaHRtbHRhZzkyIDwvYT59IGZpbGUpIHRv IHN0YXJ0IHRoZSBwcm9ncmFtIG9uIGJvb3QtdXAsIHNvIGl0IHdpbGwgcmVzdW1lIGF1dG9tYXRp Y2FsbHkgYWZ0ZXIgYSBwb3dlciBvdXRhZ2Ugb3Igb3RoZXIgcmVzdGFydC5caHRtbHJ0ZiB9XGh0 bWxydGYwIHtcKlxodG1sdGFnNzJ9XGh0bWxydGZccGFyfVxodG1scnRmMA0KDQp7XCpcaHRtbHRh ZzEwNCA8L2Rpdj59XGh0bWxydGYgfVxodG1scnRmMCANCntcKlxodG1sdGFnOTYgPGRpdj59XGh0 bWxydGYge1xodG1scnRmMCB7XCpcaHRtbHRhZzY0fVxodG1scnRmIHtcaHRtbHJ0ZjAgXGh0bWxy dGYge1xodG1scnRmMCBUaGF0IHdheSB0aGUgb25seSB0aGluZyBsb3N0IGlzIHdoYXRldmVyIHdh cyBkb25lIGFmdGVyIHRoZSBsYXN0IGNoZWNrcG9pbnQuDQp7XCpcaHRtbHRhZzg0ICZuYnNwO31c aHRtbHJ0ZiBcJ2EwXGh0bWxydGYwICBUaGlzIGFsd2F5cyB3b3JrcyBhbmQgaXMgaW5kZXBlbmRl bnQgb2YgbWFjaGluZSwgbGFuZ3VhZ2UsIG9yIG9wZXJhdGluZyBzeXN0ZW0uXGh0bWxydGYgfVxo dG1scnRmMCB7XCpcaHRtbHRhZzcyfVxodG1scnRmXHBhcn1caHRtbHJ0ZjANCg0Ke1wqXGh0bWx0 YWcxMDQgPC9kaXY+fVxodG1scnRmIH1caHRtbHJ0ZjAgDQp7XCpcaHRtbHRhZzk2IDxkaXY+fVxo dG1scnRmIHtcaHRtbHJ0ZjAge1wqXGh0bWx0YWc2NH1caHRtbHJ0ZiB7XGh0bWxydGYwIFxodG1s cnRmIHtcaHRtbHJ0ZjAgU3RldmUgVHJveVxodG1scnRmIH1caHRtbHJ0ZjAge1wqXGh0bWx0YWc3 Mn1caHRtbHJ0ZlxwYXJ9XGh0bWxydGYwDQoNCntcKlxodG1sdGFnMTA0IDwvZGl2Pn1caHRtbHJ0 ZiB9XGh0bWxydGYwIA0Ke1wqXGh0bWx0YWc5NiA8ZGl2Pn1caHRtbHJ0ZiB7XGh0bWxydGYwIA0K e1wqXGh0bWx0YWcxMTIgPGJyPn1caHRtbHJ0ZiBccGFyDQpcaHRtbHJ0ZjAgDQp7XCpcaHRtbHRh ZzEwNCA8L2Rpdj59XGh0bWxydGYgfVxodG1scnRmMCANCntcKlxodG1sdGFnMjQ4IDwvc3Bhbj59 DQp7XCpcaHRtbHRhZzU4IDwvYm9keT59DQp7XCpcaHRtbHRhZzI3IDwvaHRtbD59DQp7XCpcaHRt bHRhZzMgXHBhciB9DQp7XCpcaHRtbHRhZzY0IDxwPn1caHRtbHJ0ZiBccGFyDQpcaHRtbHJ0ZjAg XGh0bWxydGYge1xodG1scnRmMCANCntcKlxodG1sdGFnNCBccGFyIH0tLS0tDQp7XCpcaHRtbHRh ZzQgXHBhciB9XGh0bWxydGYgIFxodG1scnRmMCBUbyB1bnN1YnNjcmliZSwgc2VuZCBhIG1lc3Nh Z2Ugd2l0aCBib2R5ICJTSUdOT0ZGIEJMQUNLQk9YIiB0byBMSVNUU0VSVkBMSVNUUy5PQkVST04u Q0gNCntcKlxodG1sdGFnNCBccGFyIH1caHRtbHJ0ZiAgXGh0bWxydGYwIFxodG1scnRmfX0Ac2lv bjogMS4wDQpNZXM ----boundary-LibPST-iamunique-1099044961_-_--- Received on Fri Jun 17 2011 - 16:57:41 UTC